Field of medicine concerned with the determination of causes, incidence, and characteristic behavior of disease outbreaks affecting human populations. It includes the interrelationships of host, agent, and environment as related to the distribution and control of disease.
Any deviation of results or inferences from the truth, or processes leading to such deviation. Bias can result from several sources: one-sided or systematic variations in measurement from the true value (systematic error); flaws in study design; deviation of inferences, interpretations, or analyses based on flawed data or data collection; etc. There is no sense of prejudice or subjectivity implied in the assessment of bias under these conditions.
The application of molecular biology to the answering of epidemiological questions. The examination of patterns of changes in DNA to implicate particular carcinogens and the use of molecular markers to predict which individuals are at highest risk for a disease are common examples.
The introduction of error due to systematic differences in the characteristics between those selected and those not selected for a given study. In sampling bias, error is the result of failure to ensure that all members of the reference population have a known chance of selection in the sample.
The number of new cases of a given disease during a given period in a specified population. It also is used for the rate at which new events occur in a defined population. It is differentiated from PREVALENCE, which refers to all cases, new or old, in the population at a given time.
The influence of study results on the chances of publication and the tendency of investigators, reviewers, and editors to submit or accept manuscripts for publication based on the direction or strength of the study findings. Publication bias has an impact on the interpretation of clinical trials and meta-analyses. Bias can be minimized by insistence by editors on high-quality research, thorough literature reviews, acknowledgement of conflicts of interest, modification of peer review practices, etc.
A cancer registry mandated under the National Cancer Act of 1971 to operate and maintain a population-based cancer reporting system, reporting periodically estimates of cancer incidence and mortality in the United States. The Surveillance, Epidemiology, and End Results (SEER) Program is a continuing project of the National Cancer Institute of the National Institutes of Health. Among its goals, in addition to assembling and reporting cancer statistics, are the monitoring of annual cancer incident trends and the promoting of studies designed to identify factors amenable to cancer control interventions. (From National Cancer Institute, NIH Publication No. 91-3074, October 1990)
The total number of cases of a given disease in a specified population at a designated time. It is differentiated from INCIDENCE, which refers to the number of new cases in the population at a given time.
An aspect of personal behavior or lifestyle, environmental exposure, or inborn or inherited characteristic, which, on the basis of epidemiologic evidence, is known to be associated with a health-related condition considered important to prevent.
Sudden increase in the incidence of a disease. The concept includes EPIDEMICS and PANDEMICS.
Research techniques that focus on study designs and data gathering methods in human and animal populations.
Factors that can cause or prevent the outcome of interest, are not intermediate variables, and are not associated with the factor(s) under investigation. They give rise to situations in which the effects of two processes are not separated, or the contribution of causal factors cannot be separated, or the measure of the effect of exposure or risk is distorted because of its association with other factors influencing the outcome of the study.
Ongoing scrutiny of a population (general population, study population, target population, etc.), generally using methods distinguished by their practicability, uniformity, and frequently their rapidity, rather than by complete accuracy.
The form and structure of analytic studies in epidemiologic and clinical research.
The frequency of different ages or age groups in a given population. The distribution may refer to either how many or what proportion of the group. The population is usually patients with a specific disease but the concept is not restricted to humans and is not restricted to medicine.
An infant during the first month after birth.
The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
The relationships of groups of organisms as reflected by their genetic makeup.
Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.
Divisions of the year according to some regularly recurrent phenomena usually astronomical or climatic. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)
A set of statistical methods used to group variables or observations into strongly inter-related subgroups. In epidemiology, it may be used to analyze a closely grouped series of events or cases of disease or other health-related phenomenon with well-defined distribution patterns in relation to time or place or both.
Procedures for identifying types and strains of bacteria. The most frequently employed typing systems are BACTERIOPHAGE TYPING and SEROTYPING as well as bacteriocin typing and biotyping.
Any infection which a patient contracts in a health-care institution.
A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
Studies used to test etiologic hypotheses in which inferences about an exposure to putative causal factors are derived from data relating to characteristics of persons under study or to events or experiences in their past. The essential feature is that some of the persons under study have the disease or outcome of interest and their characteristics are compared with those of unaffected persons.
Branch of medicine concerned with the prevention and control of disease and disability, and the promotion of physical and mental health of the population on the international, national, state, or municipal level.
Gel electrophoresis in which the direction of the electric field is changed periodically. This technique is similar to other electrophoretic methods normally used to separate double-stranded DNA molecules ranging in size up to tens of thousands of base-pairs. However, by alternating the electric field direction one is able to separate DNA molecules up to several million base-pairs in length.
A technique for identifying individuals of a species that is based on the uniqueness of their DNA sequence. Uniqueness is determined by identifying which combination of allelic variations occur in the individual at a statistically relevant number of different loci. In forensic studies, RESTRICTION FRAGMENT LENGTH POLYMORPHISM of multiple, highly polymorphic VNTR LOCI or MICROSATELLITE REPEAT loci are analyzed. The number of loci used for the profile depends on the ALLELE FREQUENCY in the population.
Maleness or femaleness as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or effect of a circumstance. It is used with human or animal concepts but should be differentiated from SEX CHARACTERISTICS, anatomical or physiological manifestations of sex, and from SEX DISTRIBUTION, the number of males and females in given circumstances.
Studies in which subsets of a defined population are identified. These groups may or may not be exposed to factors hypothesized to influence the probability of the occurrence of a particular disease or other outcome. Cohorts are defined populations which, as a whole, are followed in an attempt to determine distinguishing subgroup characteristics.
Professionals, technicians, and assistants staffing LABORATORIES.
The number of males and females in a given population. The distribution may refer to how many men or women or what proportion of either in the group. The population is usually patients with a specific disease but the concept is not restricted to humans and is not restricted to medicine.
Process of determining and distinguishing species of bacteria or viruses based on antigens they share.
Genotypic differences observed among individuals in a population.
Elements of limited time intervals, contributing to particular results or situations.
The concept pertaining to the health status of inhabitants of the world.
A plan for collecting and utilizing data so that desired information can be obtained with sufficient precision or so that an hypothesis can be tested properly.
Deoxyribonucleic acid that makes up the genetic material of bacteria.
In vitro method for producing large amounts of specific DNA or RNA fragments of defined length and sequence from small amounts of short oligonucleotide flanking sequences (primers). The essential steps include thermal denaturation of the double-stranded target molecules, annealing of the primers to their complementary sequences, and extension of the annealed primers by enzymatic synthesis with DNA polymerase. The reaction is efficient, specific, and extremely sensitive. Uses for the reaction include disease diagnosis, detection of difficult-to-isolate pathogens, mutation analysis, genetic testing, DNA sequencing, and analyzing evolutionary relationships.
The systems and processes involved in the establishment, support, management, and operation of registers, e.g., disease registers.
Time period from 1901 through 2000 of the common era.
Application of statistical procedures to analyze specific observed or assumed facts from a particular study.
The qualitative or quantitative estimation of the likelihood of adverse effects that may result from exposure to specified health hazards or from the absence of beneficial influences. (Last, Dictionary of Epidemiology, 1988)
Using MOLECULAR BIOLOGY techniques, such as DNA SEQUENCE ANALYSIS; PULSED-FIELD GEL ELECTROPHORESIS; and DNA FINGERPRINTING, to identify, classify, and compare organisms and their subtypes.
Substances that reduce the growth or reproduction of BACTERIA.
Variation occurring within a species in the presence or length of DNA fragment generated by a specific endonuclease at a specific site in the genome. Such variations are generated by mutations that create or abolish recognition sites for these enzymes or change the length of the fragment.
Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (DISEASE VECTORS) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks.
Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.
The exposure to potentially harmful chemical, physical, or biological agents in the environment or to environmental factors that may include ionizing radiation, pathogenic organisms, or toxic chemicals.
The relating of causes to the effects they produce. Causes are termed necessary when they must always precede an effect and sufficient when they initiate or produce an effect. Any of several factors may be associated with the potential disease causation or outcome, including predisposing factors, enabling factors, precipitating factors, reinforcing factors, and risk factors.
The transmission of infectious disease or pathogens. When transmission is within the same species, the mode can be horizontal or vertical (INFECTIOUS DISEASE TRANSMISSION, VERTICAL).
Studies which start with the identification of persons with a disease of interest and a control (comparison, referent) group without the disease. The relationship of an attribute to the disease is examined by comparing diseased and non-diseased persons with regard to the frequency or levels of the attribute in each group.
A country spanning from central Asia to the Pacific Ocean.
New abnormal growth of tissue. Malignant neoplasms show a greater degree of anaplasia and have the properties of invasion and metastasis, compared to benign neoplasms.
Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.
Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.
Direct nucleotide sequencing of gene fragments from multiple housekeeping genes for the purpose of phylogenetic analysis, organism identification, and typing of species, strain, serovar, or other distinguishable phylogenetic level.
The largest of the continents. It was known to the Romans more specifically as what we know today as Asia Minor. The name comes from at least two possible sources: from the Assyrian asu (to rise) or from the Sanskrit usa (dawn), both with reference to its being the land of the rising sun, i.e., eastern as opposed to Europe, to the west. (From Webster's New Geographical Dictionary, 1988, p82 & Room, Brewer's Dictionary of Names, 1992, p34)
Infectious diseases that are novel in their outbreak ranges (geographic and host) or transmission mode.
The ratio of two odds. The exposure-odds ratio for case control data is the ratio of the odds in favor of exposure among cases to the odds in favor of exposure among noncases. The disease-odds ratio for a cohort or cross section is the ratio of the odds in favor of disease among the exposed to the odds in favor of disease among the unexposed. The prevalence-odds ratio refers to an odds ratio derived cross-sectionally from studies of prevalent cases.
Studies in which the presence or absence of disease or other health-related variables are determined in each member of the study population or in a representative sample at one particular time. This contrasts with LONGITUDINAL STUDIES which are followed over a period of time.
Diseases of non-human animals that may be transmitted to HUMANS or may be transmitted from humans to non-human animals.
Sudden outbreaks of a disease in a country or region not previously recognized in that area, or a rapid increase in the number of new cases of a previous existing endemic disease. Epidemics can also refer to outbreaks of disease in animal or plant populations.
Parliamentary democracy located between France on the northeast and Portugual on the west and bordered by the Atlantic Ocean and the Mediterranean Sea.
Time period from 2001 through 2100 of the common era.
A country in western Europe bordered by the Atlantic Ocean, the English Channel, the Mediterranean Sea, and the countries of Belgium, Germany, Italy, Spain, Switzerland, the principalities of Andorra and Monaco, and by the duchy of Luxembourg. Its capital is Paris.
Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).
A quantitative method of combining the results of independent studies (usually drawn from the published literature) and synthesizing summaries and conclusions which may be used to evaluate therapeutic effectiveness, plan new studies, etc., with application chiefly in the areas of research and medicine.
The inhabitants of rural areas or of small towns classified as rural.
The activities and endeavors of the public health services in a community on any level.
Collection, analysis, and interpretation of data about the frequency, distribution, and consequences of disease or health conditions, for use in the planning, implementing, and evaluating public health programs.
A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.
The science dealing with the earth and its life, especially the description of land, sea, and air and the distribution of plant and animal life, including humanity and human industries with reference to the mutual relations of these elements. (From Webster, 3d ed)
Events, characteristics, or other definable entities that have the potential to bring about a change in a health condition or other defined outcome.
Invertebrates or non-human vertebrates which transmit infective organisms from one host to another.
A republic in central Africa lying east of CHAD and the CENTRAL AFRICAN REPUBLIC and west of NIGERIA. The capital is Yaounde.
INFLAMMATION of any segment of the GASTROINTESTINAL TRACT from ESOPHAGUS to RECTUM. Causes of gastroenteritis are many including genetic, infection, HYPERSENSITIVITY, drug effects, and CANCER.
Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)
The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.
EPIDEMIOLOGIC STUDIES based on the detection through serological testing of characteristic change in the serum level of specific ANTIBODIES. Latent subclinical infections and carrier states can thus be detected in addition to clinically overt cases.
Computer-based representation of physical systems and phenomena such as chemical processes.
A set of three nucleotides in a protein coding sequence that specifies individual amino acids or a termination signal (CODON, TERMINATOR). Most codons are universal, but some organisms do not produce the transfer RNAs (RNA, TRANSFER) complementary to all codons. These codons are referred to as unassigned codons (CODONS, NONSENSE).
Theoretical representations that simulate the behavior or activity of genetic processes or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.
The probability that an event will occur. It encompasses a variety of measures of the probability of a generally unfavorable outcome.
Institutions with an organized medical staff which provide medical care to patients.
Predetermined sets of questions used to collect data - clinical data, social status, occupational group, etc. The term is often applied to a self-completed survey instrument.
Individuals whose ancestral origins are in the continent of Europe.
The confinement of a patient in a hospital.
Statistical models which describe the relationship between a qualitative dependent variable (that is, one which can take only certain discrete values, such as the presence or absence of a disease) and an independent variable. A common application is in epidemiology for estimating an individual's risk (probability of a disease) as a function of a given risk factor.
Evaluation undertaken to assess the results or consequences of management and procedures used in combating disease in order to determine the efficacy, effectiveness, safety, and practicability of these interventions in individual cases or series.
The ability of bacteria to resist or to become tolerant to chemotherapeutic agents, antimicrobial agents, or antibiotics. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).
A group of people with a common cultural heritage that sets them apart from others in a variety of social relationships.
Infections with bacteria of the genus STAPHYLOCOCCUS.
Theoretical representations that simulate the behavior or activity of systems, processes, or phenomena. They include the use of mathematical equations, computers, and other electronic equipment.
A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.
The condition of harboring an infective organism without manifesting symptoms of infection. The organism must be readily transmissible to another susceptible host.
Systematic gathering of data for a particular purpose from various sources, including questionnaires, interviews, observation, existing records, and electronic devices. The process is usually preliminary to statistical analysis of the data.
Animals considered to be wild or feral or not adapted for domestic use. It does not include wild animals in zoos for which ANIMALS, ZOO is available.
Extensive collections, reputedly complete, of facts and data garnered from material of a specialized subject area and made available for analysis and application. The collection can be automated by various contemporary methods for retrieval. The concept should be differentiated from DATABASES, BIBLIOGRAPHIC which is restricted to collections of bibliographic references.
The systematic surveying, mapping, charting, and description of specific geographical sites, with reference to the physical features that were presumed to influence health and disease. Medical topography should be differentiated from EPIDEMIOLOGY in that the former emphasizes geography whereas the latter emphasizes disease outbreaks.
Programs of surveillance designed to prevent the transmission of disease by any means from person to person or from animal to man.
The presence of viable bacteria circulating in the blood. Fever, chills, tachycardia, and tachypnea are common acute manifestations of bacteremia. The majority of cases are seen in already hospitalized patients, most of whom have underlying diseases or procedures which render their bloodstreams susceptible to invasion.
Procedures for finding the mathematical function which best describes the relationship between a dependent variable and one or more independent variables. In linear regression (see LINEAR MODELS) the relationship is constrained to be a straight line and LEAST-SQUARES ANALYSIS is used to determine the best fit. In logistic regression (see LOGISTIC MODELS) the dependent variable is qualitative rather than continuously variable and LIKELIHOOD FUNCTIONS are used to find the best relationship. In multiple regression, the dependent variable is considered to depend on more than a single independent variable.
Groups of individuals whose putative ancestry is from native continental populations based on similarities in physical appearance.
An increased liquidity or decreased consistency of FECES, such as running stool. Fecal consistency is related to the ratio of water-holding capacity of insoluble solids to total water, rather than the amount of water present. Diarrhea is not hyperdefecation or increased fecal weight.
Social and economic factors that characterize the individual or group within the social structure.
The presence of co-existing or additional diseases with reference to an initial diagnosis or with reference to the index condition that is the subject of study. Comorbidity may affect the ability of affected individuals to function and also their survival; it may be used as a prognostic indicator for length of hospital stay, cost factors, and outcome or survival.
Aspects of health and disease related to travel.
The smallest continent and an independent country, comprising six states and two territories. Its capital is Canberra.
The inhabitants of a city or town, including metropolitan areas and suburban areas.
Works about clinical trials that involve at least one test treatment and one control treatment, concurrent enrollment and follow-up of the test- and control-treated groups, and in which the treatments to be administered are selected by a random process, such as the use of a random-numbers table.
The proportion of survivors in a group, e.g., of patients, studied and followed over a period, or the proportion of persons in a specified group alive at the beginning of a time interval who survive to the end of the interval. It is often studied using life table methods.
The region of southwest Asia and northeastern Africa usually considered as extending from Libya on the west to Afghanistan on the east. (From Webster's New Geographical Dictionary, 1988)
The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.
Virus diseases caused by CALICIVIRIDAE. They include HEPATITIS E; VESICULAR EXANTHEMA OF SWINE; acute respiratory infections in felines, rabbit hemorrhagic disease, and some cases of gastroenteritis in humans.
Time period from 1801 through 1900 of the common era.
Any of the infectious diseases of man and other animals caused by species of MYCOBACTERIUM.
Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating.
Statistical interpretation and description of a population with reference to distribution, composition, or structure.
Includes the spectrum of human immunodeficiency virus infections that range from asymptomatic seropositivity, thru AIDS-related complex (ARC), to acquired immunodeficiency syndrome (AIDS).
A prediction of the probable outcome of a disease based on a individual's condition and the usual course of the disease as seen in similar situations.
Injuries incurred during participation in competitive or non-competitive sports.
Computer systems capable of assembling, storing, manipulating, and displaying geographically referenced information, i.e. data identified according to their locations.
The largest country in North America, comprising 10 provinces and three territories. Its capital is Ottawa.
Monitoring of rate of occurrence of specific conditions to assess the stability or change in health levels of a population. It is also the study of disease rates in a specific cohort such as in a geographic area or population subgroup to estimate trends in a larger population. (From Last, Dictionary of Epidemiology, 2d ed)
The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.
A range of values for a variable of interest, e.g., a rate, constructed so that this range has a specified probability of including the true value of the variable.
Statistical formulations or analyses which, when applied to data and found to fit the data, are then used to verify the assumptions and parameters used in the analysis. Examples of statistical models are the linear model, binomial model, polynomial model, two-parameter model, etc.
A country in northern Africa, bordering the Mediterranean Sea, between Libya and the Gaza Strip, and the Red Sea north of Sudan, and includes the Asian Sinai Peninsula Its capital is Cairo.
Insects that transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.
A set of techniques used when variation in several variables has to be studied simultaneously. In statistics, multivariate analysis is interpreted as any analytic method that allows simultaneous study of two or more dependent variables.
A theorem in probability theory named for Thomas Bayes (1702-1761). In epidemiology, it is used to obtain the probability of disease in a group of people with some characteristic on the basis of the overall rate of that disease and of the likelihood of that characteristic in healthy and diseased individuals. The most familiar application is in clinical decision analysis where it is used for estimating the probability of a particular diagnosis given the appearance of some symptoms or test result.
Functions constructed from a statistical model and a set of observed data which give the probability of that data for various values of the unknown model parameters. Those parameter values that maximize the probability are the maximum likelihood estimates of the parameters.
A systematic collection of factual data pertaining to health and disease in a human population within a given geographic area.
Any infection acquired in the community, that is, contrasted with those acquired in a health care facility (CROSS INFECTION). An infection would be classified as community-acquired if the patient had not recently been in a health care facility or been in contact with someone who had been recently in a health care facility.
A class of statistical procedures for estimating the survival function (function of time, starting with a population 100% well at a given time and providing the percentage of the population still well at later times). The survival analysis is then used for making inferences about the effects of treatments, prognostic factors, exposures, and other covariates on the function.
The exposure to potentially harmful chemical, physical, or biological agents that occurs as a result of one's occupation.
Tandem arrays of moderately repetitive, short (10-60 bases) DNA sequences which are found dispersed throughout the GENOME, at the ends of chromosomes (TELOMERES), and clustered near telomeres. Their degree of repetition is two to several hundred at each locus. Loci number in the thousands but each locus shows a distinctive repeat unit.
Formerly known as Siam, this is a Southeast Asian nation at the center of the Indochina peninsula. Bangkok is the capital city.
The prediction or projection of the nature of future problems or existing conditions based upon the extrapolation or interpretation of existing scientific data or by the application of scientific methodology.
Countries in the process of change with economic growth, that is, an increase in production, per capita consumption, and income. The process of economic growth involves better utilization of natural and human resources, which results in a change in the social, political, and economic structures.
The study of chance processes or the relative frequency characterizing a chance process.
Infection with any of the rotaviruses. Specific infections include human infantile diarrhea, neonatal calf diarrhea, and epidemic diarrhea of infant mice.
Tumors or cancer of the human BREAST.
Published materials which provide an examination of recent or current literature. Review articles can cover a wide range of subject matter at various levels of completeness and comprehensiveness based on analyses of literature that may include research findings. The review may reflect the state of the art. It also includes reviews as a literary form.
The former British crown colony located off the southeast coast of China, comprised of Hong Kong Island, Kowloon Peninsula, and New Territories. The three sites were ceded to the British by the Chinese respectively in 1841, 1860, and 1898. Hong Kong reverted to China in July 1997. The name represents the Cantonese pronunciation of the Chinese xianggang, fragrant port, from xiang, perfume and gang, port or harbor, with reference to its currents sweetened by fresh water from a river west of it.
Research that involves the application of the natural sciences, especially biology and physiology, to medicine.
Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.
A preconceived judgment made without factual basis.
Diseases of domestic cattle of the genus Bos. It includes diseases of cows, yaks, and zebus.
Critical and exhaustive investigation or experimentation, having for its aim the discovery of new facts and their correct interpretation, the revision of accepted conclusions, theories, or laws in the light of newly discovered facts, or the practical application of such new or revised conclusions, theories, or laws. (Webster, 3d ed)
The study of microorganisms living in a variety of environments (air, soil, water, etc.) and their pathogenic relationship to other organisms including man.
Studies in which variables relating to an individual or group of individuals are assessed over a period of time.
The science and art of collecting, summarizing, and analyzing data that are subject to random variation. The term is also applied to the data themselves and to the summarization of the data.
The ability of bacteria to resist or to become tolerant to several structurally and functionally distinct drugs simultaneously. This resistance may be acquired through gene mutation or foreign DNA in transmissible plasmids (R FACTORS).
Enzymes found in many bacteria which catalyze the hydrolysis of the amide bond in the beta-lactam ring. Well known antibiotics destroyed by these enzymes are penicillins and cephalosporins.
Studies in which individuals or populations are followed to assess the outcome of exposures, procedures, or effects of a characteristic, e.g., occurrence of disease.
The process of leaving one's country to establish residence in a foreign country.
Infections with bacteria of the species ESCHERICHIA COLI.
Individuals whose ancestral origins are in the continent of Africa.
An acute viral infection in humans involving the respiratory tract. It is marked by inflammation of the NASAL MUCOSA; the PHARYNX; and conjunctiva, and by headache and severe, often generalized, myalgia.
The proportion of patients with a particular disease during a given year per given unit of population.
Inhaling and exhaling the smoke of burning TOBACCO.
A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.
Federal program, created by Public Law 89-97, Title XVIII-Health Insurance for the Aged, a 1965 amendment to the Social Security Act, that provides health insurance benefits to persons over the age of 65 and others eligible for Social Security benefits. It consists of two separate but coordinated programs: hospital insurance (MEDICARE PART A) and supplementary medical insurance (MEDICARE PART B). (Hospital Administration Terminology, AHA, 2d ed and A Discursive Dictionary of Health Care, US House of Representatives, 1976)
The external elements and conditions which surround, influence, and affect the life and development of an organism or population.
The relative amounts of the PURINES and PYRIMIDINES in a nucleic acid.
The age, developmental stage, or period of life at which a disease or the initial symptoms or manifestations of a disease appear in an individual.
Organized periodic procedures performed on large groups of people for the purpose of detecting disease.
Notification or reporting by a physician or other health care provider of the occurrence of specified contagious diseases such as tuberculosis and HIV infections to designated public health agencies. The United States system of reporting notifiable diseases evolved from the Quarantine Act of 1878, which authorized the US Public Health Service to collect morbidity data on cholera, smallpox, and yellow fever; each state in the US has its own list of notifiable diseases and depends largely on reporting by the individual health care provider. (From Segen, Dictionary of Modern Medicine, 1992)
The restriction of a characteristic behavior, anatomical structure or physical system, such as immune response; metabolic response, or gene or gene variant to the members of one species. It refers to that property which differentiates one species from another but it is also used for phylogenetic levels higher or lower than the species.
Infections with bacteria of the genus STREPTOCOCCUS.
Animals which have become adapted through breeding in captivity to a life intimately associated with humans. They include animals domesticated by humans to live and breed in a tame condition on farms or ranches for economic reasons, including LIVESTOCK (specifically CATTLE; SHEEP; HORSES; etc.), POULTRY; and those raised or kept for pleasure and companionship, e.g., PETS; or specifically DOGS; CATS; etc.
Hospital units providing continuous surveillance and care to acutely ill patients.
Persons living in the United States having origins in any of the black groups of Africa.
The monitoring of the level of toxins, chemical pollutants, microbial contaminants, or other harmful substances in the environment (soil, air, and water), workplace, or in the bodies of people and animals present in that environment.
Diseases which have one or more of the following characteristics: they are permanent, leave residual disability, are caused by nonreversible pathological alteration, require special training of the patient for rehabilitation, or may be expected to require a long period of supervision, observation, or care. (Dictionary of Health Services Management, 2d ed)
All of Africa except Northern Africa (AFRICA, NORTHERN).
Statistical models in which the value of a parameter for a given value of a factor is assumed to be equal to a + bx, where a and b are constants. The models predict a linear regression.
A highly contagious infectious disease caused by the varicella-zoster virus (HERPESVIRUS 3, HUMAN). It usually affects children, is spread by direct contact or respiratory route via droplet nuclei, and is characterized by the appearance on the skin and mucous membranes of successive crops of typical pruritic vesicular lesions that are easily broken and become scabbed. Chickenpox is relatively benign in children, but may be complicated by pneumonia and encephalitis in adults. (From Dorland, 27th ed)
Byrt, Ted; Bishop, Janet; Carlin, John B. (1993). "Bias, prevalence and kappa". Journal of Clinical Epidemiology. 46 (5): 423- ... He is Head of Data Science and Director of the Clinical Epidemiology and Biostatistics Unit at the Murdoch Children's Research ... American Journal of Epidemiology. 171 (5): 624-632. doi:10.1093/aje/kwp425. PMID 20106935. Gelman, Andrew; Carlin, John B.; ... Institute (MCRI) and a professor in the Centre for Epidemiology and Biostatistics in the Melbourne School of Population and ...
I. Genealogic epidemiology of inbreeding". American Journal of Epidemiology. 125 (3): 453-461. doi:10.1093/oxfordjournals.aje. ... Khoury, M. J.; Cohen, B. H.; Newill, C. A.; Bias, W.; McKusick, V. A. (1987). "Inbreeding and prereproductive mortality in the ... Genealogic epidemiology of prereproductive mortality". American Journal of Epidemiology. 125 (3): 462-472. doi:10.1093/ ... Direct and indirect effects of inbreeding". American Journal of Epidemiology. 125 (3): 473-483. doi:10.1093/oxfordjournals.aje. ...
Riggs, Jack E. (1993). "Stone-age genes and modern lifestyle: Evolutionary mismatch or differential survival bias". Journal of ... Riggs published in the Journal of Clinical Epidemiology in 1993.[7] In the years to follow, the term evolutionary mismatch has ...
Causes included selection bias, media bias and incorrect reporting by governments. Selection bias in epidemiology occurs when ... "Observational studies and bias in epidemiology" (PDF). College board. 2004. Archived (PDF) from the original on 23 April 2009. ... Media bias may have skewed incidence maps based on these media reports. Countries with poor health care systems and poor ... Twenty five samples were sent to the Caribbean Epidemiology Center. Cuba suspended flights to and from Mexico for 48 hours. The ...
"Funnel plots for detecting bias in meta-analysis: guidelines on choice of axis". Journal of Clinical Epidemiology. 54 (10): ... "Misleading funnel plot for detection of bias in meta-analysis". Journal of Clinical Epidemiology. 53 (5): 477-484. doi:10.1016/ ... researchers could not visually identify publication bias". Journal of Clinical Epidemiology. 58 (9): 894-901. doi:10.1016/j. ... A funnel plot is a graph designed to check for the existence of publication bias; funnel plots are commonly used in systematic ...
A major issue has been publication bias, where positive results are more likely to be published in journals. This has been ... European Journal of Epidemiology. 18 (8): 817-22. doi:10.1023/A:1025343720564. PMID 12974558. S2CID 19059757. CAM use [in the ... Jeffrey D. Scargle (2000). "Publication Bias: The "file-drawer problem" in scientific inference" (PDF). Journal of Scientific ... and selection bias. Since better quality trials have become available, the evidence for efficacy of homeopathy preparations has ...
Unblinded data analysts may favor an analysis that supports their existing beliefs (confirmation bias). These biases are ... A systematic review of trials randomizing patients to blind and nonblind sub-studies". International Journal of Epidemiology. ... observer bias, confirmation bias, and other sources. A blind can be imposed on any participant of an experiment, including ... Bias due to poor blinding tends to favor the experimental group, resulting in inflated effect size and risk of false positives ...
... he joined the UCLA Epidemiology faculty in 1980 where he became Professor of Epidemiology in the Fielding School of Public ... Greenland, S. (January 1, 2005). "Multiple-bias modeling for analysis of observational data (with discussion)". Journal of the ... He is the co-author of a leading advanced textbook on epidemiology (currently in its 3rd edition). He was made a Fellow of the ... doi:10.1111/j.1467-985x.2004.00349.x. Rothman, K. J.; Greenland, S.; Lash, T. L. (2008). Modern Epidemiology (3rd ed.). ...
Weed DL, Kramer BS (1996). "Induced abortion, bias, and breast cancer: why epidemiology hasn't reached its limit". J. Natl. ... The meta-analysis was criticized in the Journal of the National Cancer Institute for ignoring the role of response bias and for ... Journal of Epidemiology and Community Health. 50 (5): 481-96. doi:10.1136/jech.50.5.481. PMC 1060338. PMID 8944853. ... a "blurring of association with causation." It was also criticized for selection bias by using studies with widely varying ...
Zhang, D; Freemantle, N; Cheng, KK (January 2011). "Are randomized trials conducted in China or India biased? A comparative ... Journal of Clinical Epidemiology. 66 (1): 10-22. doi:10.1016/j.jclinepi.2011.11.011. PMID 22459428. Kay, M. (4 January 2013). " ... Journal of Clinical Epidemiology. 64 (8): 925-6. doi:10.1016/j.jclinepi.2011.03.002. PMID 21704256. Vaidyanathan, Gayathri (3 ... Social Psychiatry and Psychiatric Epidemiology. 50 (10): 1527-36. doi:10.1007/s00127-015-1037-y. PMID 25735517. S2CID 71600. ...
A Study Constructed from Atomic Radiation, Morality, Epidemiology, Science, Bias, Philosophy and Death. Aberystwyth: Green ...
Mackenzie SG, Lippman A (January 1989). "An investigation of report bias in a case-control study of pregnancy outcome". ... American Journal of Epidemiology. 129 (1): 65-75. doi:10.1093/oxfordjournals.aje.a115125. PMID 2910073. "MedDRA MSSO , MedDRA ...
Publication bias is cited as a concern in the reviews of randomized controlled trials of acupuncture. A 1998 review of studies ... Ma B, Qi GQ, Lin XT, Wang T, Chen ZM, Yang KH (September 2012). "Epidemiology, quality, and reporting characteristics of ... The same review noted that "It is difficult to draw conclusion [sic] because the included studies have a high risk of bias and ... Su CX, Han M, Ren J, Li WY, Yue SJ, Hao YF, Liu JP (January 2015). "Empirical evidence for outcome reporting bias in randomized ...
January 2016). "ROBIS: A new tool to assess risk of bias in systematic reviews was developed". Journal of Clinical Epidemiology ... Risk of bias' assessments. Systematic reviews of such a bias may amplify the effect, although it is important to note that the ... Page MJ, McKenzie JE, Kirkham J, Dwan K, Kramer S, Green S, Forbes A (October 2014). "Bias due to selective inclusion and ... Roberts I. "Retraction Of Scientific Papers For Fraud Or Bias Is Just The Tip Of The Iceberg". IFL Science!. Retrieved 29 June ...
Social desirability bias results from inconsistency between attitudes and behaviors. This is because although people may have ... International Journal of Epidemiology. 24 (2): 389-398. doi:10.1093/ije/24.2.389. ISSN 0300-5771. PMID 7635601. Grzyb, Tomasz ... Therefore, the ways in which attitudes are biased by social desirability may be interesting in its own right. Therefore, social ... Reports of attitudes and behaviors may be subject to social desirability bias. Even in cases where respondents are anonymous, ...
1997). "Participation bias in a sexuality survey: psychological and behavioural characteristics of responders and non- ... responders". International Journal of Epidemiology. 26 (4): 844-54. doi:10.1093/ije/26.4.844. PMID 9279618. Bailey JM (1995). " ...
... is a term used within spatial epidemiology to refer to when ecological bias results as a consequence of ... This bias is prevented by adjusting in the same way both the exposure and disease rates. This adjustment is rarely possible as ... Spatial Epidemiology: Methods and Applications. Oxford University Press, Oxford.. ...
One such hypothesis is the Salmon Bias, which suggests that Hispanics tend to return home towards the end of their life, ... American Journal of Epidemiology. 109 (2): 186-204. doi:10.1093/oxfordjournals.aje.a112674. PMID 425958. Turra CM, Elo IT (2008 ... It appears that the Hispanic paradox cannot be explained by either the "salmon bias hypothesis" or the "healthy migrant effect ... A second popular hypothesis, called the "Salmon Bias", attempts to factor in the occurrence of returning home. This hypothesis ...
Assessing Potential Biases". Paediatric and Perinatal Epidemiology. 29 (1): 72-81. doi:10.1111/ppe.12160. ISSN 1365-3016. PMID ... Journal of Epidemiology and Community Health. 73 (8): 768-777. doi:10.1136/jech-2018-211819. hdl:10547/623278. PMID 31010821. ...
The terminology "reverse epidemiology" was first proposed by Kamyar Kalantar-Zadeh in the journal Kidney International in 2003 ... The obesity paradox has been criticized on the grounds of being an artifact arising from biases in observational studies. ... One probable methodological explanation for the obesity paradox is collider stratification bias, which commonly emerges when ... Kalantar-Zadeh, Kamyar; Block, Gladys; Humphreys, Michael H.; Kopple, Joel D. (2003). "Reverse epidemiology of cardiovascular ...
This association is subject to minimal bias due to unmeasured confounding by severity of addiction. "Butrans Medication Guide ... Epidemiology. 29 (2): 261-268. doi:10.1097/EDE.0000000000000780. PMC 5792296. PMID 29112519. Methadone is associated with ...
Epidemiology Reviews, 8:106 16;1986. Armenian HK, Zurayk HC, Kazandjian VA: The Epidemiology of Infant Deaths in the Armenian ... Armenian HK: Enrollment Bias and Variation in Clinical Manifestations: A Review of Consecutive Cases of Familial Paroxysmal ... American Journal of Epidemiology 136(6):761-762, 1992. Manual of Epidemiology for District Health Management Edited by J.P. ... Epidemiology Reviews 16(1):109-123;1994. Armenian HK, Gordis L. Future Perspectives on the Case-Control Method. Epidemiology ...
EpidemiologyEdit. Epilepsy is a relatively common disorder, affecting between 0.5-1% of the population,[35] and frontal lobe ... The disorder also has no gender or age bias, affecting males and females of all ages. In a recent study, the mean subject age ...
"American Journal of Epidemiology. 179 (7): 807-823. doi:10.1093/aje/kwt334. PMC 3969532. PMID 24518810.. ... Funding bias in research;[7] in all reviews of the effects of secondhand smoke on health published between 1980 and 1995, the ... Epidemiology, physiology, and biochemistry". Circulation. 83 (1): 1-12. doi:10.1161/01.cir.83.1.1. PMID 1984876.. ... Annals of Epidemiology. 23 (10): 652-61. doi:10.1016/j.annepidem.2013.07.001. PMID 23969303.. ...
... in particular publication bias and outcome reporting bias. She is retired (as of December 31, 2018) Professor Emerita in the ... Kay Dickersin is an academic who trained first in cell biology and subsequently epidemiology. She went on to a career studying ... She was awarded a PhD in epidemiology from the Johns Hopkins School of Hygiene and Public Health in 1989. While an ... While at Fullerton College, and through her biology students, Dickersin learned about the field of epidemiology, which she ...
Bradford Hill criteria Causal inference Epidemiology Molecular pathological epidemiology Molecular pathology Pathogenesis ... Events may occur together simply due to chance, bias or confounding, instead of one event being caused by the other. It is also ... In epidemiology, several lines of evidence together are required to infer causation. Sir Austin Bradford-Hill demonstrated a ... Further thinking in epidemiology was required to distinguish causation from association or statistical correlation. ...
... is the index biased?". Journal of Clinical Epidemiology. 55 (3): 296-305. doi:10.1016/s0895-4356(01)00471-1. PMID 11864801. " ... Bias and racism also contribute to disparities in health outcomes. Non-white racial groups may experience bias and racism ... Whether it be at a hospital, a walk-in clinic, or a family doctor's office, people are hit with bias-based comments concerning ... It has been argued that other cases of inequalities in health care reflect a systemic bias in the way medical procedures and ...
Work pattern causes bias in self-reported activity duration: a randomised study of mechanisms and implications for exposure ... assessment and epidemiology. Occup Environ Med. 2009 Jan; 66(1):38-44. PMID 18805887; PMC 3257319. Drazen JM, D'Agostino RB, ...
A Survey and Register Study of the Impact of Sex-Specific Selection and Information Bias". Annals of Epidemiology. 19 (7): 504- ... Data collected from a research study in Denmark indicated that the paradox is likely due, in part, to selection bias. Women ...
In the absence of this bias, especially for diseases that are not expected to get better by themselves such as cancer or HIV ... Kienle GS, Kiene H (December 1997). "The powerful placebo effect: fact or fiction?". Journal of Clinical Epidemiology. 50 (12 ... Even those with positive results can be better explained as resulting in false positives due to bias and noisy data.[177] ... These studies tend to have a variety of problems, such as small samples, various biases, poor research design, lack of controls ...
Asadi-Pooya AA, Sperling MR (May 2015). "Epidemiology of psychogenic nonepileptic seizures". Epilepsy & Behavior. 46: 60-5. doi ... the authors point out ways in which this may have biased their outcome data. Outcome was shown to be better in people with ...
A 2012 systematic review found insufficient low bias evidence to support the use of spinal manipulation as a therapy for the ... Michaleff ZA, Lin CW, Maher CG, van Tulder MW (2012). "Spinal manipulation epidemiology: Systematic review of cost ... Research published by chiropractors is distinctly biased.[4] For reviews of SM for back pain chiropractic authors tend to have ...
Epidemiology[edit]. The study of the epidemiology of Lassa fever is complicated by a lengthy incubation period, which may be up ... "Mapping Transmission Risk of Lassa Fever in West Africa: The Importance of Quality Control, Sampling Bias, and Error Weighting ... "Lassa fever: Epidemiology, clinical features, and social consequences". BMJ. 327 (7426): 1271-1275. doi:10.1136/bmj.327.7426. ... "Rodent-borne hemorrhagic fevers: under-recognized, widely spread and preventable - epidemiology, diagnostics and treatment" ...
Another major application for these methods is in epidemiology,[3] where they are used to estimate the completeness of ... The Lincoln-Petersen estimator is asymptotically unbiased as sample size approaches infinity, but is biased at small sample ... Chapman also found the estimator could have considerable negative bias for small Kn/N [9](page 146), but was unconcerned ... and has been used in both ecology and epidemiology for detecting animal or human diseases,[12] respectively. ...
EpidemiologyEdit. The WHO estimates that in 2012 there were 285 million visually impaired people in the world, of which 246 ... a topic on which an individual is unaware of their own biases, and therefore of the resulting distortions of their own ... Eye Trauma Epidemiology and Prevention Archived 2006-05-28 at the Wayback Machine ... in which information is kept from either the experimenter or the participant to mitigate the placebo effect or observer bias. ...
A Source of Bias?". International Journal of Osteoarchaeology. 23 (2): 186-196. doi:10.1002/oa.2285. ISSN 1099-1212. Milella, ... sex and age with investigations of demography and epidemiology in order to verify or critique socioeconomic conditions ...
Bias, discrimination, and obesity. Obes. Res. (Review). 2001-12, 9 (12): 788-805. PMID 11743063. doi:10.1038/oby.2001.108.. ... European Journal of Epidemiology. 2011, 26 (6): 457-461. ISSN 0393-2990. PMC 3115050. PMID 21461943. doi:10.1007/s10654-011- ... Epidemiology - definition and classification of obesity In:. Peter G. Kopelman, Ian D. Caterson, Michael J. Stock, William H. ... Yang W, Kelly T, He J. Genetic epidemiology of obesity. Epidemiol Rev (Review). 2007, 29: 49-61. PMID 17566051. doi:10.1093/ ...
The medicalization of lactose intolerance as a disorder has been attributed to biases in research history (since most early ... Epidemiology[edit]. Rough rates of lactose intolerance in different regions of the world ...
Contemporary precision, bias and accuracy of minimum post-mortem intervals estimated using development of carrion-feeding ...
"United Settles Sex-Bias Case". New York Times. July 11, 1986.. *^ a b Quindlen, Anna (May 16, 1993). "Public & Private; In Thin ... "Epidemiology. 26 (2): 192-203. doi:10.1097/EDE.0000000000000225. ISSN 1044-3983. PMC 4510952. PMID 25563432.. ...
Lauwereyns, Jan (February 2010). The Anatomy of Bias: How Neural Circuits Weigh the Options. Cambridge, Massachusetts: The MIT ...
Despite this, it is often adequate to illustrate the broader patterns of life's history.[28] There are also biases in the ... "Sampling bias, gradual extinction patterns and catastrophes in the fossil record". Geological Implications of Impacts of Large ...
In genetic epidemiology, a genome-wide association study (GWA study, or GWAS) is an examination of all or most of the genes ( ... The result is a form of ascertainment bias. This has sometimes created an impression that Jews are more susceptible to genetic ...
"American Journal of Epidemiology. 176 Suppl 7 (Suppl 7): S44-54. doi:10.1093/aje/kws264. PMC 3530364. PMID 23035144.. ... reported that 8 out of 10 meta-analyses assessed whether weight loss outcomes could have been affected by publication bias, and ...
There are four major categories of model-based biases: prestige bias, skill bias, success bias, and similarity bias. A " ... Borrowing heavily from population genetics and epidemiology, this book built a mathematical theory concerning the spread of ... There are two major categories of context biases: model-based biases, and frequency-dependent biases. Model-based biases result ... Content biases are sometimes called "direct biases." Context biases result from individuals using clues about the social ...
Kennedy G.J. The epidemiology of late-life depression. In: Kennedy G. J, editor. Suicide and depression in late life: Critical ... Mahzarin R. Banaji and Anthony G. Greenwald, Blind Spot: Hidden Biases of Good People (Random House, 2013), 67. ... Hidden Biases of Good People, a book about the test, reports that 80% of Americans have an "automatic preference for the young ... American Journal of Epidemiology Vol 106, No 1, pp. 17-32 ...
Yang, W.; Kelly, T.; He, J. (2007). "Genetic epidemiology of obesity". Epidemiol Rev. Vol. 29. str. 49-61. doi:10.1093/epirev/ ... Puhl R; Brownell KD (december 2001). "Bias, discrimination, and obesity". Obes. Res. Vol. 9 no. 12. str. 788-805. doi:10.1038/ ... Seidell, J.C. (2005). "Epidemiology - definition and classification of obesity". V Peter G. Kopelman, Ian D. Caterson, Michael ...
Epidemiology. Disability-adjusted life year rates for posttraumatic stress disorder per 100,000 inhabitants in 2004.[201]. .mw- ... the use of a multi-measure approach eliminates the bias associated with any given instrument ....". ... Social Psychiatry and Psychiatric Epidemiology. 50 (4): 525-37. doi:10.1007/s00127-014-0978-x. PMID 25398198.. ... Most of the current reliable data regarding the epidemiology of PTSD is based on DSM-IV criteria, as the DSM-5 was not ...
Response bias[edit]. Survey results may be affected by response bias, where the answers given by respondents do not reflect ... That is, the actual sample is a biased version of the universe the pollster wants to analyze. In these cases, bias introduces ... Nonresponse bias[edit]. Since some people do not answer calls from strangers, or refuse to the answer the poll, poll samples ... Coverage bias[edit]. Another source of error is the use of samples that are not representative of the population as a ...
Methods that adjust for bias (such as using propensity score matching methods) assume that a complete health record is captured ...
Gender and sex bias[edit]. In 2014, it was announced that the NIH is directing scientists to perform their experiments with ... NIDKK operates the Phoenix Epidemiology and Clinical Research Branch in Phoenix, AZ. ... the division of Cancer Epidemiology and Genetics and the division of Cancer Treatment and Diagnosis.[22] ...
Standard Practice for Use of the Terms Precision and Bias in ASTM Test Methods, ASTM International, ASTM E177. (subscription ... Epidemiology/. methods. *occurrence: Incidence (Cumulative incidence). *Prevalence *Point. *Period. *association: absolute ( ...
The Times also noted an "anti-male bias in cancer funding" with a four-to-one discrepancy in the United Kingdom by both the ... Hsing AW, Chokkalingam AP (2006). "Prostate cancer epidemiology". Frontiers in Bioscience. 11: 1388-413. doi:10.2741/1891. PMID ... Dennis LK, Dawson DV (January 2002). "Meta-analysis of measures of sexual activity and prostate cancer". Epidemiology. 13 (1): ... Wakai K (February 2005). "[Descriptive epidemiology of prostate cancer in Japan and Western countries]". Nippon Rinsho (in ...
Case for Non-Biased Intelligence Testing Against Black Africans Has Not Been Made: A Comment on Rushton, Skuy, and Bons (2004) ... International Journal of Epidemiology 35(3): 534-536 doi:10.1093/ije/dyl065 ... Jensen, A.R. (1979). Bias in mental testing. New York (NY): Free Press. ISBN 0-029-16430-3.. ...
"Structural Equation Modeling". Encyclopedia of Epidemiology. 2008. doi:10.4135/9781412953948.n443. ISBN 978-1-4129-2816-8.. ... weak external validity of some accepted models and philosophical bias inherent to the standard procedures.[10] ...
A good way to prevent biases potentially leading to false positives in the data collection phase is to use a double-blind ... Epidemiology/. methods. *occurrence: Incidence (Cumulative incidence). *Prevalence *Point. *Period. *association: absolute ( ... False positive conclusions, often resulting from the pressure to publish or the author's own confirmation bias, are an inherent ...
2000). Epidemiology, Open University Press, Buckingham.[129]. *Mohan, John; Barnard, Steve; Jones, Kelvyn and Twigg, Lizbeth ( ... In particular, the authors' treatment of 'heterogeneity bias' clarifies the importance of addressing both 'within' and 'between ... Extracts of Epidemiology on ,Research Gate ...
These include access to health care, completeness and accuracy in medical records, observer bias, patient satisfaction, and ... An opportunity arose to study epidemiology and health services administration at Harvard, where he received his MPH degree ( ...
In epidemiology, Information bias refers to bias arising from measurement error.[1] Information bias is also referred to as ... epidemiology). *. Moren, Alain; Valenciano, Marta (Kitching, Aileen, ed.). "Information (measurement) bias". Field Epidemiology ... The occurrence of information biases may not be independent of the occurrence of selection biases. ... observational bias and misclassification. A Dictionary of Epidemiology, sponsored by the International Epidemiological ...
Epidemiology Doubts. By Robin Hanson · September 17, 2007 6:00 am · Comments (33) · « Prev · Next » ... The effect of healthy-user bias has the potential for big mischief throughout these large epidemiologic studies. … At its ... Medicine Morality NearFar Personal Politics Prediction Markets Psychology Regulation Signaling Social Science Standard Biases ...
7. Greenland S. Quantifying biases in causal models: classical confounding vs collider-stratification bias. Epidemiology. 2003; ... Bias formulas for sensitivity analysis for direct and indirect effects. Epidemiology. 2010;21:540-551. * Cited Here... , ... A structural approach to selection bias. Epidemiology. 2004;15:615-625. * Cited Here... , ... Notably, there is no bias if U has the same relative effect on heart failure risk among obese and normal weight persons. Bias ...
10 These estimates are well-known to be subject to biases such as social response bias and recall bias (1, 2). However, ... Bias Associated With Self-Report of Prior Screening Mammography. Kathleen A. Cronin, Diana L. Miglioretti, Martin Krapcho, ... Bias Associated With Self-Report of Prior Screening Mammography. Kathleen A. Cronin, Diana L. Miglioretti, Martin Krapcho, ... Bias Associated With Self-Report of Prior Screening Mammography. Kathleen A. Cronin, Diana L. Miglioretti, Martin Krapcho, ...
In epidemiology, Information bias refers to bias arising from measurement error. Information bias is also referred to as ... The occurrence of information biases may not be independent of the occurrence of selection biases. 2. Bias in an estimate ... Kitching, Aileen (ed.). "Information (measurement) bias". Field Epidemiology Manual. FEM Wiki. Archived from the original on ... A Dictionary of Epidemiology, sponsored by the International Epidemiological Association, defines this as the following: "1. A ...
... by healthcare access bias, length-biased sampling, Neyman bias, competing risks, or survivor treatment selection bias. In ... Investigator bias and interviewer bias: the problem of systematic error in epidemiology. J Clin Epidemiol1994;47:825-7. ... Neyman bias: (synonyms: incidence-prevalence bias, selective survival bias) when a series of survivors is selected, if the ... Dissemination bias: the biases associated to the whole publication process, from biases in the retrieval of information ( ...
The bias consistently results in underestimating recent transmission and the impact of risk factors for recent transmission. ... I demonstrate the potential bias in estimates of recent transmission and the impact of risk factors for clustering by using ... Among the goals of the molecular epidemiology of infectious disease are to quantify the extent of ongoing transmission of ... Sampling Bias in the Molecular Epidemiology of Tuberculosis On This Page Methods Results Discussion Appendix 1 Appendix 2 Cite ...
Precision and Bias of Food Frequency-based Measures of Fruit and Vegetable Intakes. Alan R. Kristal, Nancy C. Vizenor, Ruth E. ... We examined bias and precision for: (a) total fruit and vegetables; (b) total fruit and vegetables minus fried vegetables (to ... We defined bias as the difference between mean FFQ-based measures of fruit and vegetable intake and a self-reported criterion ... Bias and precision are presented from three large studies that collected a FFQ-based measure and at least one independent ...
Sampling Bias in the Molecular Epidemiology of Tuberculosis Megan B. Murray. Author affiliation: Harvard School of Public ... Sampling Bias in the Molecular Epidemiology of Tuberculosis. ...
American Journal of Epidemiology, Annals of Epidemiology, Epidemiology, and the Journal of Clinical Epidemiology (formerly the ... Is there a sex bias in choosing editors? Epidemiology journals as an example. Submitted by KBL781 on Mon, 2011-08-01 16:50. ... Is there a sex bias in choosing editors? Epidemiology journals as an example. ... Is there a sex bias in choosing editors? Epidemiology journals as an example. ...
Selection bias Victor J. Schoenbach, PhD Department of Epidemiology ... Principles of Epidemiology for Public Health (EPID600) Sources of error: ... Epidemiology, Paradise Lost , Romeo and Juliet, selection bias, Study design, St. Pauls School, Horwitz ... 3/15/2011 Sources of error: Selection bias 8 Accuracy, Bias, Error, Precision, Reliability, Validity • Accuracy : lack of error ...
We propose the use of administrative record-linkage and novel methodology to overcome non-response bias, and illustrate this ... Conclusion Corrected estimates suggest non-response bias leads to an underestimation of overall alcohol consumption as well as ... OP07 Adjusting survey-based estimates of alcohol consumption in Scotland for non-response bias: record-linkage study ... OP07 Adjusting survey-based estimates of alcohol consumption in Scotland for non-response bias: record-linkage study ...
The results from our study show the importance of evaluating testing bias in epidemiological studies obtaining data from ... In this study we evaluated testing bias for neutrophil counts in clinical practice by using results from requested and non- ... However, testing bias is an issue in all centers and should be evaluated to be able to adjust for this bias. Using laboratory ... Sackett DL: Bias in analytic research. J Chronic Dis. 1979, 32: 51-63. 10.1016/0021-9681(79)90012-2View ArticlePubMedGoogle ...
The PROBIT method showed bias for each of the ten simulated populations, but the direction and magnitude of the average bias ... In a manner similar to Dale, our study further investigated the bias and precision of the PROBIT method for different sample ... The PROBIT method will provide gains in precision regardless of the sample size, but the method may be biased. The direction ... For a given simulated population, the average bias was relatively constant for all sample sizes drawn. The 95% half-width ...
... overview on epidemiology and the Internet for medical and health related students around the world based on the concept of ... Bias and Confounding. Part I. Topic: statistics. Author: Nigel Paneth. Keywords: bias and confounding. Versions:. In English: ...
Some suggest that publication biases occur in mainstream medicine, and may also occur in CAM. Homeopathy is one of the most ... Type I and II errors, surveillance, prescription or publication bias as well as the healthy user effect are described. ... We also assessed mindfulness-based therapy trial registrations for indications of possible reporting bias and reviewed recent ... These questions illustrate some statistical problems and some bias encountered during clinical studies, which can lead to ...
Validity and Bias in Epidemiology, builds on the fundamental concepts taught in the previous courses to discuss bias and ... Excellent concise course on the fundamental aspects of epidemiology related to validity, bias, confounding and effect ... Principales reseñas sobre VALIDITY AND BIAS IN EPIDEMIOLOGY. ... In this course you will learn about the main types of bias and ... The first course of the specialisation, Measuring Disease in Epidemiology, looks into the main measures used in epidemiology ...
... overview on epidemiology and the Internet for medical and health related students around the world based on the concept of ... Topic: epidemiology. Author: Dona Schneider. Keywords: bias confounding chance. Versions:. In Spanish: View lecture*Original: ... Bias, Confounding and the Role of Chance. Part I (in Spanish 8361) translated by Nicolas Padilla - Sesgo, confusión y el papel ...
Automatically cite a software in EMERGING-THEMES-IN-EPIDEMIOLOGY by using Citation Machines free citation generator. ... Creating accurate citations in EMERGING-THEMES-IN-EPIDEMIOLOGY has never been easier! ... Bias. *Does the author or the organization have a bias? Does bias make sense in relation to your argument? ...
Bias. Sampling of practices and patients. To reduce bias, we will recruit a stratified random sample of practices in the East ... To reduce reviewer bias, e-learning and face-to-face training will be provided to GP reviewers on human factors in healthcare, ... Bias may be introduced if more than a small minority of patients objects to a review of their records. ... Understanding the epidemiology of avoidable significant harm in primary care: protocol for a retrospective cross-sectional ...
Is Probabilistic Bias Analysis Approximately Bayesian?. MacLehose, Richard F.; Gustafson, Paul MacLehose, Richard F.; Gustafson ... Commentary: Reference-test Bias in Diagnostic-test Evaluation A Problem for Epidemiologists, too. Miller, William C. ... Accounting for Bias Due to Selective Attrition: The Example of Smoking and Cognitive Decline. Weuve, Jennifer; Tchetgen ... Conditioning on Intermediates in Perinatal Epidemiology. VanderWeele, Tyler J.; Mumford, Sunni L.; Schisterman, Enrique F. ...
West Coast Stat Views (on Observational Epidemiology and more) Comments, observations and thoughts from two left coast bloggers ... Survivor bias There has been some discussion about meony from parents leading to a lower GPA from both Andrew Gelman and I. One ... on applied statistics, higher education and epidemiology. Joseph is a new assistant professor. Mark is a marketing statistician ...
Validity and Bias in Epidemiology. This module is dedicated to dealing with confounding. Confounding can be addressed either ... Validity and Bias in Epidemiology. Imperial College London. ... In this course you will learn about the main types of bias and ... We will finish the course with a broader discussion of causality in epidemiology and we will highlight how you can utilise all ... We will also briefly discuss about the Directed Acyclic Graphs, which is a novel way to detect bias and confounding and control ...
BIAS. Deviation of results or inferences from the truth, or processes leading to such systematic deviation. Any trend in the ... ANALYTIC EPIDEMIOLOGY. The aspect of epidemiology concerned with the search for health-related causes and effects. Uses ... DESCRIPTIVE EPIDEMIOLOGY. The aspect of epidemiology concerned with organizing and summarizing health-related data according to ... APPLIED EPIDEMIOLOGY. The application or practice of epidemiology to address public health issues. ...
Methods are presented for the assessment and control of confounding, misclassification bias, and selection bias. Strengths and ... Epidemiology. Intermediate Epidemiology. SPH EP 813 (4 credits). The purpose of this course is to further develop the ... bias, and confounding. The primary aims of the course are to provide working knowledge of the fundamentals of epidemiology as ... and biases. This hands-on course will put the concepts of intermediate epidemiology into application as the students perform a ...
autism spectrum disorders; epidemiology; health disparities; prevalence. PMID:. 30892923. PMCID:. PMC6824598. [Available on ... Assessment of racial and ethnic bias in autism spectrum disorder prevalence estimates from a US surveillance system.. Imm P1, ...
Epidemiology, present status, and risk factors. Summary. As for the dynamic trends of esophageal carcinoma in Japan, the ... Many of the studies were judged to a high risk of bias in the study quality evaluation performed using Quality Assessment of ... Efforts to prevent academic bias unique to the society. Efforts were made to avoid academic COI of any single academic ... Each retrieved article was subjected to a primary and a secondary screening, summarized, and then assessed for bias, besides ...
Biases in randomized trials: a conversation between trialists and epidemiologists. Epidemiology [forthcoming].. ... of bias in one domain means the effect estimate from the study is at serious risk of bias or worse, even if the risk of bias is ... selection bias and forms of measurement bias such as differential misclassification), the bias needs to be thought of as an ... excluding studies at higher risk of bias) might be considered, either within specific bias domains or overall. Risk of bias ...
Assortative mixing as a source of bias in epidemiological studies of sexually transmitted infections: the case of smoking and ... American Journal of Epidemiology 2004; 160: 393-402. 27. Liljeros, F, Edling, CR, Nunes Amaral, LA. Sexual networks: ... Journal of Epidemiology and Biostatistics 2001; 6: 393-407. 4. Furber, AS, et al. Is smoking tobacco an independent risk factor ... American Journal of Epidemiology 1991; 133: 1199-1209. 16. Wolf, R, Freedman, D. Cigarette smoking, sexually transmitted ...
  • Kleinbaum et al , 2 based on Olli S Miettinen's ideas, classified biases in three main groups: selection bias, information bias, and confounding. (
  • Steineck and Ahlbom, 6 based on the Miettinen's concept of study base, considered in this order, confounding, misclassification (similar to information bias), misrepresentation (which has a narrower meaning than selection bias), and analysis deviation. (
  • Steineck and Ahlbom keep confounding apart from biases in the statistical analysis as it typically occurs when the actual study base differs from the "ideal" study base, in which there is no association between different determinants of an effect. (
  • Confounding bias is kept apart from biases in data analysis (according to the ideas of Steineck and Ahlbom 6 and Maclure and Schneeweiss 5 ). (
  • Bias and Confounding. (
  • Bias, Confounding and the Role of Chance. (
  • We will also briefly discuss about the Directed Acyclic Graphs, which is a novel way to detect bias and confounding and control for them. (
  • The material covered is intended to broaden and extend the student's understanding of the elements of study design, data analysis, and inference in epidemiologic research, including issues related to causation, bias, and confounding. (
  • Methods are presented for the assessment and control of confounding, misclassification bias, and selection bias. (
  • Possible bias and confounding and their impact on study results in Spatial Epidemiology were analyzed in given examples. (
  • LIMITATIONS Biases other than unmeasured confounding were not analytically assessed. (
  • Residual confounding from unmeasured factors may still exist and bias the estimation. (
  • The possibility that the association among women interviewed by telephone is causal and that the lack of association among mail respondents is due to bias, confounding, or apparently chance fluctuations is shown to be unlikely. (
  • However, unlike correcting for confounding bias using inverse weighting, uptake of inverse probability-of-censoring weighted estimation as well as competing methods has been limited in the applied epidemiologic literature. (
  • The gold standard for inference in community interventions is a community-randomized trial because the design eliminates confounding bias ( 2 ). (
  • Estimating causal effects from observational studies in severe malaria patients is difficult due to both confounding and selection bias. (
  • The diagrams I have used to explain confounding and mediation in observational studies are simple versions of the so-called directed acyclic graphs (DAGs) that have been used to facilitate understanding of confounding in epidemiology. (
  • The simpler treatment I have presented here should provide researchers with sufficient understanding to be meticulous about design and analysis of their own observational studies and wary of the confounding that inevitably biases the effects in published observational studies. (
  • The effect of healthy-user bias has the potential for 'big mischief' throughout these large epidemiologic studies. (
  • The primary aims of the course are to provide working knowledge of the fundamentals of epidemiology as well as to serve as a foundation for more advanced study of epidemiologic methods. (
  • The main goal of the proposed study is to assess the impacts of epidemiologic biases in World Trade Center (WTC) health studies by identifying the presence of bias and then by quantifying and adjusting for the bias effects. (
  • Other topics include foundations of modern epidemiology, the epidemiologic transition, reemergence of infectious disease, social inequalities in health, and ethical issues. (
  • He guides you from an explanation of the epidemiologic approach to disease and intervention, through the use of epidemiologic principles to identify the causes of disease, to a discussion of how epidemiology should be used to improve evaluation and public policy. (
  • New to this edition: Master the latest nuances in epidemiology thanks to a wealth of new and updated illustrations, examples, and epidemiologic data. (
  • 3 - Basic Epidemiologic Methods for Cancer Investigations", Essentials of Surgical Oncology, Surgical Foundations, Philadelphia: Mosby, pp. 21-38, ISBN 978-0-8151-4385-7, retrieved 2021-01-14 Lead time bias - General Practice Notebook Gordis, Leon (2008). (
  • Cross-sectional study of 4 US epidemiology journals, American Journal of Epidemiology, Annals of Epidemiology, Epidemiology, and the Journal of Clinical Epidemiology (formerly the Journal of Chronic Diseases), for 1982, 1987, 1992, and 1994. (
  • [1] Information bias is also referred to as observational bias and misclassification . (
  • Metformin and the Risk of Cancer: Time-Related Biases in Observational Studies. (
  • In all, we thank the authors for this opportunity to clarify the bias and hope our article provides some methodological guidelines useful to avoid some of the vexing time-related biases in observational studies of important drug effects. (
  • The objectives of this observational study were to describe the methodological quality of neonatal randomized controlled trials and quantify the bias related to specific methodological and study-level characteristics. (
  • CONCLUSIONS: This observational study of a sample of neonatal trials showed that most were at high risk of bias, indicating that there is room for improvement in the design, conduct and reporting of neonatal trials to ensure valid results for the most clinically important outcomes. (
  • This occurs with post hoc analysis that may lead to a publication bias when significant results are more frequently reported. (
  • Type I and II errors, surveillance, prescription or publication bias as well as the healthy user effect are described. (
  • Publication bias has an impact on the interpretation of clinical trials and meta-analyses. (
  • To render it meaningful, "bias" must be linked to another word (such as selection bias, recall bias and publication bias). (
  • In this study we evaluated testing bias for neutrophil counts in clinical practice by using results from requested and non-requested hematological blood tests. (
  • The results from our study show the importance of evaluating testing bias in epidemiological studies obtaining data from clinical databases. (
  • Such selective processes might induce testing bias in clinical database studies. (
  • However, testing bias might occur because of underlying disease or medication use, as neutrophil counts differ in several diseases and clinical observations have shown that patients using glucocorticoids often have higher neutrophil counts. (
  • Requesting neutrophil counts specifically for certain diseases or for glucocorticoid users might cause testing bias in clinical databases. (
  • These questions illustrate some statistical problems and some bias encountered during clinical studies, which can lead to erroneous results. (
  • This material serves as brief overview and an introduction to the uses, methodology and clinical application of epidemiology. (
  • The association between traditional cardiovascular risk factors and an adverse clinical outcome in CHF patients is referred to as "reverse epidemiology. (
  • First, we have summarized the major methodological problems presented by the previous acupuncture studies and then have discussed the appropriate methods for the experimental design based on the principles of clinical epidemiology. (
  • At the end of this chapter, we advocate establishment of a new interdisciplinary, namely Clinical Acupunctural Epidemiology that will focus on the methodology of acupuncture studies and aid the future of acupuncture research. (
  • This article introduces a 20-part series providing guidance for the use of GRADE methodology that will appear in the Journal of Clinical Epidemiology. (
  • By me in the Journal of Clinical Epidemiology. (
  • Me and a dozen other academics all just wrote basically the same thing about Open Science in the Journal Of Clinical Epidemiology. (
  • A Clinical Trial with Combined Transcranial Direct Current Stimulation and Attentional Bias Modification in Alcohol Dependent Patients. (
  • This unit introduces the concept of clinical epidemiology and provides students with core skills in clinical epidemiology at an introductory level. (
  • The first occurrence of the term "evolutionary mismatch" may have been in a paper by Jack E. Riggs published in the Journal of Clinical Epidemiology in 1993. (
  • In clinical investigations, a bias is any systematic factor other than the intervention of interest that affects the magnitude of (i.e. tends to increase or decrease) an observed difference in the outcomes of a treatment group and a control group. (
  • We propose the use of administrative record-linkage and novel methodology to overcome non-response bias, and illustrate this using the 2003 Scottish Health Survey measures of alcohol consumption. (
  • This methodology offers a promising route for advancing efforts to resolve non-response bias. (
  • The disadvantage of the PROBIT method is that the bias of the PROBIT methodology depends upon the deviation of the true population of WHZ from the assumed normal distribution of WHZ defined by the mean and standard deviation. (
  • The successful completion of the proposed bias analysis will assist other researchers to draw plausible inference of WTC health effects and other future disaster studies by adjusting for bias. (
  • Author for correspondence: Dr M. Brisson , Centre de recherche du CHU de Québec , Axe Santé des populations et pratiques optimales en santé , 1050 Chemin Sainte-Foy , Québec , Canada , G1S 4L8 . (
  • Cohort studies are often preferred to case-control studies because they are less susceptible to certain biases. (
  • Immortal time bias is increasingly common in cohort studies of drug effects. (
  • Selection bias due to loss to follow up represents a threat to the internal validity of estimates derived from cohort studies. (
  • To motivate greater use of inverse probability-of-censoring weighted estimation and competing methods, we use causal diagrams to describe the sources of selection bias in cohort studies employing a time-to-event framework when the quantity of interest is an absolute measure (e.g., absolute risk, survival function) or relative effect measure (e.g., risk difference, risk ratio). (
  • Estimating bias from loss to follow-up in a prospective cohort study of bicycle crash injuries. (
  • We estimated the magnitude and direction of such bias in a prospective cohort study of crash injury among cyclists. (
  • Case-control studies are often preferred in epidemiology over cohort studies because they are faster and more cost effective. (
  • When case-control studies are selected over cohort studies, special attention must be paid to selection bias. (
  • Evaluation of non-response bias in a cohort study of World Trade Center terrorist attack survivors. (
  • National estimates of the use of cancer screening procedures are based primarily on self-reported results from the National Health Interview Survey (NHIS) 9 and the Behavior Risk Factor Surveillance System (BRFSS), 10 These estimates are well-known to be subject to biases such as social response bias and recall bias ( 1 , 2 ). (
  • Toward the null bias or negative bias yields estimates closer to the null value (for example, lower and closer OR to 1), whereas away from the null bias produces the opposite, higher estimates than the true ones. (
  • I demonstrate the potential bias in estimates of recent transmission and the impact of risk factors for clustering by using computer simulations to reconstruct populations of tuberculosis patients and sample from them. (
  • Implicit in the "population-based" approach to molecular epidemiology is the assumption that the results of studies based on these samples are reliable estimates of the parameters of interest in the population from which the sample was drawn. (
  • Conclusion Corrected estimates suggest non-response bias leads to an underestimation of overall alcohol consumption as well as of disparities between men living in deprived and non-deprived areas. (
  • Assessment of racial and ethnic bias in autism spectrum disorder prevalence estimates from a US surveillance system. (
  • Unlike immortal time bias, it is not possible, a priori, to predict the direction of this bias on the point estimates since it directly depends on the differential durations for exposure assessment in the cases and controls. (
  • RRs were combined in random-effects meta-analyses and pooled estimates used in bias analyses. (
  • BACKGROUND: Loss to follow-up, if related to exposures, confounders and outcomes of interest, may bias association estimates. (
  • CONCLUSIONS: Loss to follow-up was differential by demographic, cycling and behavioural risk characteristics as well as crash outcomes, but did not substantially bias association estimates of primary research interest. (
  • The importance of estimating selection bias on prevalence estimates, shortly after a disaster. (
  • Background: Few longitudinal studies of disaster cohorts have assessed both non-response bias in prevalence estimates of health outcomes and in the estimates of associations between health outcomes and disaster exposures. (
  • We examined the factors associated with non-response and the possible non-response bias in prevalence estimates and association estimates in a longitudinal study of World Trade Center (WTC) terrorist attack survivors. (
  • We then examined potential non-response bias in prevalence estimates and in exposure-outcome association estimates by comparing one-time nonparticipants (wave 3 drop-ins and drop-outs) at the two follow-up surveys with three-wave participants. (
  • Conclusion: Our results show that, despite a downward bias in prevalence estimates of health outcomes, attrition from the WTC Health Registry follow-up studies does not lead to serious bias in associations between 9/11 disaster exposures and key health outcomes. (
  • Bias and precision are presented from three large studies that collected a FFQ-based measure and at least one independent criterion measure such as food records, dietary recalls, or serum carotenoids. (
  • Identify different types of biases that may occur in epidemiological studies, in order to apply strategies to reduce such biases. (
  • The objective of this paper is to illustrate the potential impact of the assortativity bias in studies examining STI risk factors, using smoking and human papillomavirus (HPV) as an example. (
  • 5 6 However, the inappropriate accounting of follow-up time and treatment status in the design and analysis of such studies can introduce immortal time bias. (
  • To explore the biases and confoundings in Spatial Epidemiological studies . (
  • 1 ), the authors question our assertion that several of their studies suffered from time-window bias ( 2 ). (
  • Most studies had a low RoB for the domain of incomplete outcome data (89%), while 63%, 55% and 46% of trials had low RoB for sequence generation, other sources of bias, and blinding of outcome assessors, respectively. (
  • Moreover, most G × E studies do not directly assess selective processing biases and these-generally unmeasured-cognitive factors may be one important consequence of G × E interactions. (
  • Using ancestry informative markers (AIMs), we aimed to measure the African influences in Spanish populations and to explore whether these might introduce statistical bias in population-based association studies. (
  • Although the African influences estimated might be biased due to marker ascertainment, these results confirm that Northwest African genetic footprints are recognizable nowadays in the Spanish populations, particularly in Canary Islanders, and that the uneven African influences existing in these populations might increase the risk for false positives in association studies. (
  • Instead of simply dismissing all ecologic studies as unreliable, it is preferable to estimate the direction and magnitude of potential biases. (
  • ing bias in ecologic studies is quite difficult in practice. (
  • The following two types of partially ecologic studies are often used in epidemiology. (
  • Studies that measure outcome and covariates at the individual level, but exposure at the group level, are commonly used in environmental and occupational epidemiology. (
  • Selection bias have adverse impact on surveys and epidemiological studies. (
  • Selection Bias in epidemiological studies can also occur when a sample subject is chosen to be a part of the study as a result of a third variable (unmeasured variable) which is related to both the result and outcome of interest. (
  • CONCLUSIONS: Estimating actual selection bias in disaster studies gives better information about the study representativeness. (
  • Future genetic epidemiology studies in severe malaria would benefit from the use of causal reasoning. (
  • The role of report/recall bias in case-control studies of low birth weight (LBW) was investigated in women who gave birth at a tertiary hospital. (
  • Healthy worker survivor bias may occur in occupational studies due to the tendency for unhealthy individuals to leave work earlier, and consequently accrue less exposure, compared with their healthier counterparts. (
  • In asthma studies, differential reporting bias by health status should be taken into consideration. (
  • Bias may occur at all stages of a research project, such as during generation of hypotheses, planning, implementation and funding of studies, during collection, processing and interpretation of study data, as well as during publication (dissemination) of research data. (
  • In the context of such uncertainty, we present pragmatic recommendations that promote transparency and reproducibility in processes, address methodological advances in the risk-of-bias assessment, and can be applied consistently across review topics. (
  • This course offers an introduction to some of these factors and provides guidance on how to deal with bias in epidemiological research. (
  • In Spatial Epidemiology , biases related to ascertainment/numerator/denominator induced by the choice of the disease induction/latency period and mis-specification of exposure- disease model, exposure inaccuracy, spatial dependency , significance tests etc. were involved, as well as to ecological, socio-economic confoundings factors. (
  • Among the goals of the molecular epidemiology of infectious disease are to quantify the extent of ongoing transmission of infectious agents and to identify host- and strain-specific risk factors for disease spread. (
  • in addition to the lectures on epidemiology and evidence-based medicien outlined on this page, we will also spend some time learning the R statistical computing program, the material for which can be found here . (
  • Recent advances in computing power, coupled with state-of-the-art statistical methods, have greatly increased the ability of analysts to control healthy worker survivor bias. (
  • The Norwegian Large Encyclopaedia of Medicine refers to the concept of bias as: "used in statistical and empirical research when results or inferences systematically deviate from the true values. (
  • In this module we will discuss what validity actually means and we will describe the different types of systematic error, or bias that may undermine the validity of a study. (
  • Molecular epidemiology makes use of the genetic diversity within strains of infectious organisms to track the transmission of these organisms in human populations. (
  • BACKGROUND: Sometimes in descriptive epidemiology or in the evaluation of a health intervention policy change, proportions exposed to a risk factor or to an intervention are used as explanatory variables in log-linear regressions for disease incidence or mortality. (
  • This hands-on course will put the concepts of intermediate epidemiology into application as the students perform a data analysis project from start to finish. (
  • Texts: The last time I counted, there were well over 50 introductory and intermediate epidemiology texts in print. (
  • 09-SelectionBias - Principles of Epidemiology for Public. (
  • Dr. Gordis leverages his vast experience teaching this subject in the classroom to introduce the basic principles and concepts of epidemiology in a clear, uniquely memorable way. (
  • The PROBIT method showed bias for each of the ten simulated populations, but the direction and magnitude of the average bias was changed depending on the simulated population. (
  • The direction and magnitude of the bias depends on the population it is drawn from. (
  • Biases can be classified by the research stage in which they occur or by the direction of change in a estimate. (
  • Sackett 3 and Choi 4 classified biases according to the stages of research that can occur: reading up on the field, specification and selection the study sample, execution of the experimental manoeuvre, measurement of exposures/outcomes, data analysis, results interpretation and publication. (
  • One example where testing bias might occur is in physicians' requests of blood tests. (
  • Unfortunately, severe bias can occur. (
  • There are many cases where selection bias can occur. (
  • When a particular section of the population is ignored (due to various reasons such as inconvenience in collection of data) in the sample selected from the population, selection bias will occur. (
  • Bias can also occur when a certain experiment is performed over and over again and only the favorable results are reported. (
  • Self-Selecting Bias occurs only due to the researcher's judgement or the participant's choice to volunteer for the survey, whereas selection bias can occur due to various other reasons seen above (for example, time scale). (
  • Unintended bias may occur at all stages of the research process, and the researcher needs to be aware of this. (
  • [4] Statisticians have developed methods to adjust for this type of bias, which may assist somewhat in compensating for this problem when known and when it is quantifiable. (
  • The type of bias and the design affected is also given. (
  • Double blinding is a technique used to reduce this type of bias. (
  • In Norwegian, the word "skjevhet" (skewness) is often used instead of the English term "bias", as recommended in the advice to authors of the Journal of the Norwegian Medical Association ( (
  • The concept of bias is the lack of internal validity or incorrect assessment of the association between an exposure and an effect in the target population in which the statistic estimated has an expectation that does not equal the true value. (
  • The concept of bias is the lack of internal validity or incorrect assessment of the association between an exposure and an effect in the target population. (
  • Sometimes, the term bias is also used to refer to the mechanism that produces lack of internal validity. (
  • OBJECTIVE: Risk-of-bias assessment is a central component of systematic reviews but little conclusive empirical evidence exists on the validity of such assessments. (
  • Two independent reviewers assessed risk of bias (RoB) on seven domains consisting of nine items. (
  • The only domain that showed a statistically significant association with the treatment effect was selective outcome reporting: trials at unclear/high risk of bias for this domain significantly overestimated the treatment effects compared with those assessed at low risk of bias (ROR = 1.87, 95% confidence interval: 1.26-2.78). (
  • and conducting, analyzing, and presenting results of risk-of-bias assessments. (
  • Key recommendations include transparency and reproducibility of judgments, separating risk of bias from other constructs such as applicability and precision, and evaluating risk of bias per outcome. (
  • CONCLUSION: Risk-of-bias assessment remains a challenging but essential step in systematic reviews. (
  • Risk of bias assessment: (9) Application of the risk of bias assessment results. (
  • In this last paper of the series about risk of bias assessment, we introduce the application of risk of bias assessment results. (
  • Risk of bias assessment is one of the key steps in the assessment of qu. (
  • Maclure and Schneeweiss, 5 applying the causal diagram theory, offered an interesting explanation of the main sources of bias. (
  • The sources of bias in 'Spatial Epidemiology ' were both numerous and complex, that might be overestimated or underestimated on the study results. (
  • There are several strategies to minimize testing bias, including selection of proper patient populations, measuring outcomes for all study participants, blind testing, or using imputation techniques to deal with missing data [ 8 - 10 ], but these techniques do not provide insight into size and direction of testing bias. (
  • In a manner similar to Dale, our study further investigated the bias and precision of the PROBIT method for different sample sizes using simulated populations. (
  • Course examines bridging of "individual-centered" epidemiology and "macro-epidemiology" to recognize social, economic and cultural context, assess impacts on populations, and provide inputs for public health and health policy. (
  • On completion of this course students should be familiar with the major concepts and tools of epidemiology, the study of health populations, and should be able to judge the quality of evidence in health-related research literature. (
  • Este curso es parte del Global Master of Public Health completamente en línea de Imperial College London. (
  • The application or practice of epidemiology to address public health issues. (
  • The most important biases are those produced in the definition and selection of the study population, data collection, and the association between different determinants of an effect in the population. (
  • A study can yield biased results for many different reasons. (
  • In this course you will learn about the main types of bias and what effect they might have on your study findings. (
  • In epidemiology, a countable instance in the population or study group of a particular disease, health disorder, or condition under investigation. (
  • Each retrieved article was subjected to a primary and a secondary screening, summarized, and then assessed for bias, besides classification of the study design (Table 1 ). (
  • The assortativity bias caused an overestimation of the odds ratio (OR) in the simulated study after perfect adjustment for the subjects' individual-level characteristics (adjusted OR 1·51 instead of 1·00). (
  • 7 Immortal time bias is particularly problematic because it necessarily biases the results in favour of the treatment under study by conferring a spurious survival advantage to the treated group. (
  • While this may be an improvement over the breast cancer study ( 3 ), this method is still prone to time-window bias. (
  • Epidemiology refers to the study of the distribution of health related states or events including diseases and the application of this study to the control of diseases and other health problems. (
  • T helper bias towards Th1 cells is strongly associated with measures of atherosclerosis in the population-based study MESA-Inflammation (both coronary calcification and carotid wall thickness) after fully adjusting for traditional and novel CVD risk factors. (
  • The present study aims to address the misconception, also known as outcome bias, that antibiotics may be an effective treatment against the common cold by providing a "debiasing" risk communication intervention. (
  • Recall bias in a case-control study of low birth weight. (
  • In this study, it was examined whether or not combined attentional and interpretational bias modifications with university students who display social anxiety symptoms may lead to a decrea. (
  • This may include selection bias, sample bias, loss-to-follow-up bias, disease spectrum bias, referral bias, participation (response) bias, self-selection bias (i.e. that volunteer participants in a research study will often differ from those who do not accept the offer to participate). (
  • argue that researchers should have the opportunity to "request a waiver of consent from the research ethics board" (Kho ME et al, 2009) wherever such a requirement for consent may result in biased study results. (
  • The final participation in the study depends on a series of factors that individually or jointly may give rise to bias in the interpretation of results with regard to the population that the study is intended to represent. (
  • The phenomenon of selection bias encompasses more than skewness in the selection of the study population (Odierna DH et al. (
  • The occurrence of information biases may not be independent of the occurrence of selection biases . (
  • Commentary: Selection Bias as an Explanation for the Obesit. (
  • This is a special form of selection bias 4 and could arise as follows. (
  • The selection bias alternative is illustrated by the causal directed acyclic graph (DAG) shown in Figure A. In this DAG, heart failure is a "collider" on the "backdoor path" obesity→heart failure←unmeasured factors→death. (
  • The reasons for this important discrepancy, including the possibility of a selection bias favoring men, should be further investigated. (
  • Classically, efforts to reduce resultant selection bias are limited to weights based on socio-demographic characteristics which typically do not capture health differences within population sub-groups. (
  • You will learn how to identify and prevent selection bias and information bias and their variations. (
  • Topics include conceptualizing data analysis by defining an addressable research question, utilizing directed acyclic graphs (DAGs) for confounder selection, choosing appropriate exposure and outcome measurements and interpreting the results with respect to strengths, limitations, and biases. (
  • Over the past 15 years, stratification-based techniques as well as methods such as inverse probability-of-censoring weighted estimation have been more prominently discussed and offered as a means to correct for selection bias. (
  • We highlight that whether a given estimate obtained from standard methods is potentially subject to selection bias depends on the causal diagram and the measure. (
  • We first broadly describe inverse probability-of-censoring weighted estimation and then give a simple example to demonstrate in detail how inverse probability-of-censoring weighted estimation mitigates selection bias and describe challenges to estimation. (
  • The selection bias ranged between -10% and +9% for selected associations. (
  • What is Selection Bias? (
  • Selection Bias occurs when the data selected as a sample is not random enough. (
  • The result obtained from a sample that suffers selection bias does not reflect the correct conclusion. (
  • The presence of selection bias results in false results. (
  • It is a type of selection bias that occurs when a particular group or section of the population does not participate or withdraws participants from the survey. (
  • Sampling bias is another type of selection bias. (
  • Time scale can also lead to selection bias. (
  • In such cases the chances that the sample is not representative of the population (selection bias) is very high. (
  • Moreover, it gives rise to Selection Bias , where in the researcher choose the sample with specific favorable features that are in line with the results the researcher requires. (
  • Though the concepts of selection bias and self-selecting bias appear to be similar they are caused by different reasons. (
  • However, they are more sensitive to selection bias. (
  • Collider bias probably explains this negative association between G6PDd and CM, suggesting that causal interpretations of this association and the novel formulation of balancing selection in G6PDd are invalid. (
  • Most recently, she used instrumental variable techniques to correct for selection bias due survey non-participation in estimating HIV prevalence in Zambia and Botswana. (
  • Lead time bias is a type of selection bias, and can affect interpretation of the five-year survival rate, effectively making it appear that people survive longer with cancer even in cases where the course of cancer is the same as in those who were diagnosed later. (
  • What is Attrition Bias? (
  • An example of attrition bias is a test done by a shampoo company, regarding the effectiveness of the new product (anti-hair fall shampoo). (
  • Attrition bias occurs as many participants withdraw from the trial or do not use the product in the specified time limit or fail to respond altogether. (
  • attrition bias etc. (
  • Fundamental cognitive operations such as negative attentional bias (AB)-the tendency to preferentially orient attention toward threat-whereas important for survival-can markedly influence sensitivity to the environment. (
  • Randomized, placebo-controlled trial of 9 sessions of computerized attentional bias training on attentional bias and on symptoms of Posttraumatic Stress Disorder. (
  • Attentional bias modification alters intrinsic functional network of attentional control: A randomized controlled trial. (
  • No effect of attentional bias modification training in methamphetamine users receiving residential treatment. (
  • Attentional bias toward drug-related stimuli is a feature of drug addiction that is linked to craving and drug-seeking behavior. (
  • The effects of attentional bias modification on emotion regulation. (
  • In two experiments, we investigated the effects of Attentional Bias Modification (ABM) on emotion regulation, i.e. the manner in which people influence emotional experiences. (
  • Modifying attentional processes with attentional bias modification (ABM) might be a relevant add-on to treatment in addiction. (
  • The impact of non-pain goal focus on attentional bias to learned pain signals. (
  • Insights into the nature of cognitive bias, including attentional bias to threat signals, are considered pivotal to understanding (chronic) pain and related distress. (
  • We also assessed mindfulness-based therapy trial registrations for indications of possible reporting bias and reviewed recent systematic reviews and meta-analyses to determine whether reporting biases were identified. (
  • Epidemiology, by educator and epidemiologist Leon Gordis, is a introduction to this complex science. (
  • We compared baseline characteristics and crash outcomes of the baseline (2006) and follow-up (those who responded in 2009) cohorts by ratios of relative frequencies and estimated potential bias from loss to follow-up on seven exposure-outcome associations of interest by ratios of HRs. (
  • Biases in data interpretation, writing, and citing will not be discussed (see for a description of them by Sackett 3 and Choi 4 ). (
  • Bias also refers to a prejudiced or partial viewpoint that would affect someone's interpretation of a problem. (
  • In epidemiology , Information bias refers to bias arising from measurement error . (
  • These results, which were consistent across diverse participant samples, suggest that the 5 A Day method yields both biased and imprecise measures of vegetable intake and that research to improve this measure is needed. (
  • Negative cognitive biases and genetic variation have been associated with risk of psychopathology in largely independent lines of research. (
  • Cognitive biases are a hallmark of depression but there is scarce research on whether these biases can be directly modified by using specific cognitive training techniques. (
  • Bias can be minimized by insistence by editors on high-quality research, thorough literature reviews, acknowledgement of conflicts of interest, modification of peer review practices, etc. (
  • The fifith editon retains the book's simplicity and brevity, at the same time providing the reader with the core elements of epidemiology needed in health care practice and research. (
  • Bias (skewness) in research may give rise to results that fail to reflect reality. (
  • Bias constitutes a challenge in all forms of research activities. (
  • Bias" has no unambiguous or generally accepted meaning, either inside or outside the framework of research ethics. (
  • In research there are many types of bias, for which there is no generally accepted categorisation. (
  • Such bias may be quantified in a sensitivity analysis (also known as bias analysis). (
  • We propose that gene by environment (G × E) interactions may be mediated by selective cognitive biases and that certain forms of genetic 'reactivity' or 'sensitivity' may represent heightened sensitivity to the learning environment in a 'for better and for worse' manner. (
  • A simulation based sensitivity analysis, varying the strength of the known effect of G6PDd on anaemia, showed that this bias is sufficient to explain all of the observed association. (
  • There is no sense of prejudice or subjectivity implied in the assessment of bias under these conditions. (
  • Threat-related attentional biases have been identified as a possible precursor to the onset and maintenance of posttraumatic stress disorder (PTSD). (
  • In this Perspective, we suggest that biased cognitive processing of emotional information may be one critical pathway through which differential susceptibility influences psychological wellbeing. (
  • The data on heterogeneity support the previously published conclusion that differential reporting (biased recall) of this common exposure, tapwater consumption, is the likely explanation for its observed association with the risk of spontaneous abortion. (
  • The aspect of epidemiology concerned with the search for health-related causes and effects. (
  • and since the techniques of epidemiology are at the core of most media stories and squabbles on health, it's very weird that you don't hear the word more often. (
  • This perennial bestseller is an ideal introductions to epidemiology in health care. (
  • If occupational data are not analyzed using appropriate methods, this bias can result in attenuation or even reversal of the estimated effects of exposures on health outcomes. (
  • Researchers also noted that health care professionals who have an "inherent" bias toward their patients who are obese could be causing difficulties in assessing and treating these patients. (
  • Bias should be distinguished from random error or lack of precision. (
  • assessed the PROBIT method for measuring global acute malnutrition measure and found that the method was biased and the precision was superior only for sample sizes less than 150 when compared to the standard method. (
  • The PROBIT method will provide gains in precision regardless of the sample size, but the method may be biased. (
  • Bias diminishes the accuracy (though not necessarily the precision) of an observation. (