Epidemiology: 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.Bias (Epidemiology): 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.Molecular Epidemiology: 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.Selection Bias: 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.Incidence: 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.Publication Bias: 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.SEER Program: 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)Prevalence: 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.Risk Factors: 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.United StatesDisease Outbreaks: Sudden increase in the incidence of a disease. The concept includes EPIDEMICS and PANDEMICS.Epidemiologic Methods: Research techniques that focus on study designs and data gathering methods in human and animal populations.Confounding Factors (Epidemiology): 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.Population Surveillance: 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.Epidemiologic Research Design: The form and structure of analytic studies in epidemiologic and clinical research.Age Distribution: 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.Infant, Newborn: An infant during the first month after birth.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Phylogeny: The relationships of groups of organisms as reflected by their genetic makeup.Age Factors: 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.Seasons: 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)Cluster Analysis: 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.Bacterial Typing Techniques: 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.Cross Infection: Any infection which a patient contracts in a health-care institution.Sequence Analysis, DNA: A multistage process that includes cloning, physical mapping, subcloning, determination of the DNA SEQUENCE, and information analysis.Reproducibility of Results: 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.Retrospective Studies: 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.Public Health: 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.Electrophoresis, Gel, Pulsed-Field: 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.DNA Fingerprinting: 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.Sex Factors: 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.Cohort Studies: 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.Laboratory Personnel: Professionals, technicians, and assistants staffing LABORATORIES.Sex Distribution: 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.Serotyping: Process of determining and distinguishing species of bacteria or viruses based on antigens they share.Genetic Variation: Genotypic differences observed among individuals in a population.Time Factors: Elements of limited time intervals, contributing to particular results or situations.World Health: The concept pertaining to the health status of inhabitants of the world.Research Design: 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.EuropeDNA, Bacterial: Deoxyribonucleic acid that makes up the genetic material of bacteria.Polymerase Chain Reaction: 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.Registries: The systems and processes involved in the establishment, support, management, and operation of registers, e.g., disease registers.History, 20th Century: Time period from 1901 through 2000 of the common era.Data Interpretation, Statistical: Application of statistical procedures to analyze specific observed or assumed facts from a particular study.Risk Assessment: 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)Molecular Typing: 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.Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.Polymorphism, Restriction Fragment Length: 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.Disease Reservoirs: 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.Prospective Studies: 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.Environmental Exposure: 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.Causality: 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.Disease Transmission, Infectious: 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).Case-Control Studies: 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.China: A country spanning from central Asia to the Pacific Ocean.Neoplasms: 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.AfricaBrazilFeces: Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.ItalyMolecular Sequence Data: 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.IndiaMultilocus Sequence Typing: 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.MinnesotaAsia: 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)Communicable Diseases, Emerging: Infectious diseases that are novel in their outbreak ranges (geographic and host) or transmission mode.Odds Ratio: 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.Cross-Sectional Studies: 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.Zoonoses: Diseases of non-human animals that may be transmitted to HUMANS or may be transmitted from humans to non-human animals.Great BritainEpidemics: 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.Spain: Parliamentary democracy located between France on the northeast and Portugual on the west and bordered by the Atlantic Ocean and the Mediterranean Sea.History, 21st Century: Time period from 2001 through 2100 of the common era.France: 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.Microbial Sensitivity Tests: Any tests that demonstrate the relative efficacy of different chemotherapeutic agents against specific microorganisms (i.e., bacteria, fungi, viruses).Meta-Analysis as Topic: 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.Rural Population: The inhabitants of rural areas or of small towns classified as rural.Public Health Practice: The activities and endeavors of the public health services in a community on any level.Epidemiological Monitoring: 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.Algorithms: A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.Geography: 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)Epidemiologic Factors: Events, characteristics, or other definable entities that have the potential to bring about a change in a health condition or other defined outcome.Disease Vectors: Invertebrates or non-human vertebrates which transmit infective organisms from one host to another.Cameroon: A republic in central Africa lying east of CHAD and the CENTRAL AFRICAN REPUBLIC and west of NIGERIA. The capital is Yaounde.Gastroenteritis: 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.Sensitivity and Specificity: 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)Evolution, Molecular: The process of cumulative change at the level of DNA; RNA; and PROTEINS, over successive generations.Seroepidemiologic Studies: 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 Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.Codon: 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).Models, Genetic: 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.Risk: The probability that an event will occur. It encompasses a variety of measures of the probability of a generally unfavorable outcome.Hospitals: Institutions with an organized medical staff which provide medical care to patients.Questionnaires: 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.European Continental Ancestry Group: Individuals whose ancestral origins are in the continent of Europe.Hospitalization: The confinement of a patient in a hospital.Logistic Models: 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.Treatment Outcome: 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.EnglandDrug Resistance, Bacterial: 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).Ethnic Groups: A group of people with a common cultural heritage that sets them apart from others in a variety of social relationships.Staphylococcal Infections: Infections with bacteria of the genus STAPHYLOCOCCUS.Models, Theoretical: 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.Communicable DiseasesGenetic Predisposition to Disease: A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.Carrier State: The condition of harboring an infective organism without manifesting symptoms of infection. The organism must be readily transmissible to another susceptible host.Data Collection: 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, Wild: 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.Databases, Factual: 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.Topography, Medical: 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.Communicable Disease Control: Programs of surveillance designed to prevent the transmission of disease by any means from person to person or from animal to man.Bacteremia: 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.Regression Analysis: 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.Continental Population Groups: Groups of individuals whose putative ancestry is from native continental populations based on similarities in physical appearance.Diarrhea: 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.Socioeconomic Factors: Social and economic factors that characterize the individual or group within the social structure.Comorbidity: 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.Travel: Aspects of health and disease related to travel.Australia: The smallest continent and an independent country, comprising six states and two territories. Its capital is Canberra.Urban Population: The inhabitants of a city or town, including metropolitan areas and suburban areas.Randomized Controlled Trials as Topic: 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.Survival Rate: 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.Middle East: 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)Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.North AmericaCaliciviridae Infections: 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.History, 19th Century: Time period from 1801 through 1900 of the common era.Tuberculosis: Any of the infectious diseases of man and other animals caused by species of MYCOBACTERIUM.Attention: Focusing on certain aspects of current experience to the exclusion of others. It is the act of heeding or taking notice or concentrating.Demography: Statistical interpretation and description of a population with reference to distribution, composition, or structure.HIV Infections: Includes the spectrum of human immunodeficiency virus infections that range from asymptomatic seropositivity, thru AIDS-related complex (ARC), to acquired immunodeficiency syndrome (AIDS).Prognosis: 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.Athletic Injuries: Injuries incurred during participation in competitive or non-competitive sports.Geographic Information Systems: Computer systems capable of assembling, storing, manipulating, and displaying geographically referenced information, i.e. data identified according to their locations.Canada: The largest country in North America, comprising 10 provinces and three territories. Its capital is Ottawa.Sentinel Surveillance: 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)Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.Confidence Intervals: 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.WalesModels, Statistical: 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.Egypt: 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.Insect Vectors: Insects that transmit infective organisms from one host to another or from an inanimate reservoir to an animate host.Multivariate Analysis: 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.Bayes Theorem: 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.Likelihood Functions: 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.JapanHealth Surveys: A systematic collection of factual data pertaining to health and disease in a human population within a given geographic area.Community-Acquired Infections: 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.Survival Analysis: 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.Occupational Exposure: The exposure to potentially harmful chemical, physical, or biological agents that occurs as a result of one's occupation.SingaporeMinisatellite Repeats: 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.Thailand: Formerly known as Siam, this is a Southeast Asian nation at the center of the Indochina peninsula. Bangkok is the capital city.Bites and StingsForecasting: 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.Developing Countries: 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.Probability: The study of chance processes or the relative frequency characterizing a chance process.Rotavirus Infections: Infection with any of the rotaviruses. Specific infections include human infantile diarrhea, neonatal calf diarrhea, and epidemic diarrhea of infant mice.IsraelBreast Neoplasms: Tumors or cancer of the human BREAST.Review Literature as Topic: 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.Hong Kong: 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.Biomedical Research: Research that involves the application of the natural sciences, especially biology and physiology, to medicine.Models, Biological: 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.Prejudice: A preconceived judgment made without factual basis.Cattle Diseases: Diseases of domestic cattle of the genus Bos. It includes diseases of cows, yaks, and zebus.Research: 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)Environmental Microbiology: The study of microorganisms living in a variety of environments (air, soil, water, etc.) and their pathogenic relationship to other organisms including man.Longitudinal Studies: Studies in which variables relating to an individual or group of individuals are assessed over a period of time.TaiwanScotlandStatistics as Topic: 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.Drug Resistance, Multiple, Bacterial: 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).beta-Lactamases: 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.Follow-Up Studies: 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.Emigration and Immigration: The process of leaving one's country to establish residence in a foreign country.Escherichia coli Infections: Infections with bacteria of the species ESCHERICHIA COLI.GermanyAfrican Continental Ancestry Group: Individuals whose ancestral origins are in the continent of Africa.Influenza, Human: 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.Morbidity: The proportion of patients with a particular disease during a given year per given unit of population.Smoking: Inhaling and exhaling the smoke of burning TOBACCO.Polymorphism, Single Nucleotide: A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.Medicare: 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)Environment: The external elements and conditions which surround, influence, and affect the life and development of an organism or population.Base Composition: The relative amounts of the PURINES and PYRIMIDINES in a nucleic acid.Age of Onset: 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.Mass Screening: Organized periodic procedures performed on large groups of people for the purpose of detecting disease.Disease Notification: 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)Species Specificity: 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.Streptococcal Infections: Infections with bacteria of the genus STREPTOCOCCUS.Animals, Domestic: 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.Intensive Care Units: Hospital units providing continuous surveillance and care to acutely ill patients.African Americans: Persons living in the United States having origins in any of the black groups of Africa.Environmental Monitoring: 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.Chronic Disease: 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)PeruAfrica South of the Sahara: All of Africa except Northern Africa (AFRICA, NORTHERN).Linear Models: 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.California
American Journal of Epidemiology. 125 (3): 453-461. PMID 3812451. Khoury, M. J.; Cohen, B. H.; Newill, C. A.; Bias, W.; ... Genealogic epidemiology of prereproductive mortality". American Journal of Epidemiology. 125 (3): 462-472. PMID 3812452. Khoury ... Direct and indirect effects of inbreeding". American Journal of Epidemiology. 125 (3): 473-483. PMID 3812453. Puffenberger, E. ...
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 ...
Clinical epidemiology is a research discipline based on the methods of epidemiology (and other scientific pursuits, notably ... Bias in analytic research. J Chronic Dis. 1979;32(1-2):51-63. doi:10.1016/0021-9681(79)90012-2 PMID 447779. Department of ... Department of Clinical Epidemiology and Biostatistics, McMaster University. How to read clinical journals: I. Why to read them ... Department of Clinical Epidemiology and Biostatistics, McMaster University. Clinical disagreement II: how to avoid it and learn ...
"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/ ... A funnel plot is a graph designed to check for the existence of publication bias; funnel plots are commonly used in systematic ... In the absence of publication bias, it assumes that studies with high precision will be plotted near the average, and studies ...
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. Fisher, Robert ... 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, ...
Weed DL, Kramer BS (1996). "Induced abortion, bias, and breast cancer: why epidemiology hasn't reached its limit". J. Natl. ... Two recent, large cohort studies, which are less susceptible to bias, showed either protection or no effect on breast cancer ... Afterwards, the director of epidemiology research for the American Cancer Society stated, "[t]his issue has been resolved ... Brind's paper was criticized in the Journal of the National Cancer Institute for ignoring the role of response bias and for a " ...
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. ... American Journal of Epidemiology. 123 (5): 781-789. PMID 3962962. Brind, J. L. (1991). "Direct radioimmunoassay of ...
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. In the years to follow, the term evolutionary mismatch has ... Clinical Epidemiology. 46: 1289-1291. doi:10.1016/0895-4356(93)90093-g - via Elsevier Science Direct. "Evolution Institute ...
A Study Constructed from Atomic Radiation, Morality, Epidemiology, Science, Bias, Philosophy and Death. Aberystwyth: Green ...
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. ... Preston, Samuel; Stokes, Andrew (2014). "Obesity Paradox: Conditioning on Disease Enhances Biases in Estimating the Mortality ... Kalantar-Zadeh, Kamyar; Block, Gladys; Horwich, Tamara; Fonarow, Gregg C (2004). "Reverse epidemiology of conventional ...
Ravnskov U., "Quotation bias in reviews of the diet-heart idea", Journal of Clinical Epidemiology 1995; 48: 713-9. Ravnskov U ...
... 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.. ...
American Journal of Epidemiology. 109 (2): 186-204. PMID 425958. Turra CM, Elo IT (2008). "The Impact of Salmon Bias on the ... 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 ... In contrast, Palloni and Arias hypothesize that this phenomenon is most likely caused by across-the-board bias in ...
EpidemiologyEdit. Epilepsy is a relatively common disorder, affecting between 0.5-1% of the population, 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 ...
... in particular publication bias and outcome reporting bias. She is Professor in the Department of Epidemiology at Johns Hopkins ... She was awarded a PhD in epidemiology from the Johns Hopkins School of Hygiene and Public Health in 1989. While an ... Kay Dickersin (born November 10, 1951) is an academic who trained first in cell biology and subsequently epidemiology. She went ... 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. ...
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, ...
Definition, epidemiology, and risk factors". BMJ. 332 (7550): 1142-4. doi:10.1136/bmj.332.7550.1142. PMC 1459603. PMID 16690673 ... The medical community's resistance to the idea that tobacco caused disease has been attributed to bias from nicotine-dependent ... "Epidemiology and Infection. 123 (1): 103-8. doi:10.1017/S095026889900271X. PMC 2810733. PMID 10487646.. ... Lipworth L, Tarone RE, McLaughlin JK (December 2006). "The epidemiology of renal cell carcinoma". The Journal of Urology. 176 ( ...
Epidemiology. There is little systematic data on the prevalence of DID. It occurs more commonly in young adults ... Bias in psychiatric diagnosis. Northvale, N.J: Jason Aronson. pp. 163-168. ISBN 0-7657-0001-8.. ... Epidemiology Research International. 2011: 1-9. doi:10.1155/2011/404538. [§1, Introduction, p.1] Most of the published clinical ... These central issues relating to the epidemiology of DID remain largely unaddressed despite several decades of research. ...
This gender bias is partly offset by the initiation of large scale epidemiology studies of women, such as the Nurses' Health ... "Boston University Sloane Epidemiology Centre. Retrieved 21 July 2016.. *. "Jacobs Institute of Women's Health". Milken ... 2014). Epidemiology of women's health. Burlington, MA: Jones & Bartlett Learning. ISBN 9780763769857. .. ... The next phase was the specific funding of large scale epidemiology studies and clinical trials focussing on women's health ...
Bias of an estimator Biased random walk (biochemistry) Biased sample - see Sampling bias Biclustering Big O in probability ... epidemiology) Combinatorial data analysis Combinatorial design Combinatorial meta-analysis Common-method variance Common mode ... Residual sum of squares Response bias Response rate (survey) Response surface methodology Response variable Restricted maximum ... unrelated regressions Seismic to simulation Selection bias Selective recruitment Self-organizing map Self-selection bias Self- ...
The experts said that CTCA's patients and SEER's patients were not compatible, and that the comparison was biased in favor of ... CTCA compared its outcomes with the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database. ...
Standard methods can fit a regression of y on w without bias. There is bias only if we then use the regression of y on w as an ... Davey Smith, G.; Phillips, A. N. (1996). "Inflation in epidemiology: 'The proof and measurement of association between two ... It may seem counter-intuitive that noise in the predictor variable x induces a bias, but noise in the outcome variable y does ... However, variability, measurement error or random noise in the x variable causes bias in the estimated slope (as well as ...
Meta-research Publication bias Replication crisis Reproducibility Project "John P. A. Ioannidis". Stanford School of Medicine ... "John P. A. Ioannidis". Department of Hygiene and Epidemiology, University of Ioannina School of Medicine. Retrieved December 31 ... He was chairman at the Department of Hygiene and Epidemiology, University of Ioannina School of Medicine as well as adjunct ...
"Quantifying selective reporting and the Proteus phenomenon for multiple datasets with similar bias". PLoS ONE 6.3 (2011): ... Journal of Clinical Epidemiology 58: 543-549. de Winter, Joost; Happee, Riender (20 June 2013). "Why Selective Publication of ... a consequence of publication bias. It is akin to the winner's curse. The term was coined by John Ioannidis and Thomas A. ...
... and estimates of publication bias may remain lower than what truly exists. Most discussions of publication bias focus on ... Page 652 in Modern Epidemiology, 3rd ed. Edited by Rothman KJ, Greenland S, Lash T. Lippincott Williams and Wilkins; 2008. ... Some have argued that a weakness of the method is that sources of bias are not controlled by the method: a good meta-analysis ... As mentioned before: a symmetrical funnel plot is a sign that there is no publication bias, as the effect size and sample size ...
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. For reviews of SM for back pain chiropractic authors tend to have ...
Davidhizar, R (1992). "Interpersonal communication: a review of eye contact". Infection Control & Hospital Epidemiology. 13 (4 ... Burgoon, J. K.; J. P. Blair & R. E. Strom (2008). "Cognitive biases and nonverbal cue availability in detecting deception. ...
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 ...
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 ... A Dictionary of Epidemiology, sponsored by the International Epidemiological Association, defines this as the following: "1. A ... Copeland, K. T.; Checkoway, H.; McMichael, A. J.; Holbrook, R. H. (1977). "Bias due to misclassification in the estimation of ...
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, ...
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 ...
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 ...
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 ...
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 ...
Validity and Bias in Epidemiology. This is the final module of the course. We start by discussing what happens when the effect ... the bias cannot explain this difference. So, whats happening? Well, sometimes a drug can be more effective in women compared ... In this course you will learn about the main types of bias and what effect they might have on your study findings. You will ... We will finish the course with a broader discussion of causality in epidemiology and we will highlight how you can utilise all ...
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, ...
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 ...
Samy Suissa, professor of epidemiology and biostatistics14. *. 1Department of Epidemiology, Biostatistics, and Occupational ... Validation of bias. To validate the presence of the immortal time bias, we repeated the same study and analyses in the same ... Other sources of bias. Our corrected results are also subject to bias, particularly confounding by indication. As diabetes ... An increased awareness of immortal time bias is warranted given the frequency with which this bias is being observed, the wide ...
Selection Bias When Estimating Average Treatment Effects Using One-sample Instrumental Variable Analysis. Hughes, Rachael A.; ... Environmental Epidemiology Hands-on Tutorial on a Modeling Framework for Projections of Climate Change Impacts on Health. ... Occupational Epidemiology Gender, Depression, and Blue-collar Work: A Retrospective Cohort Study of US Aluminum Manufacturers. ... Social Epidemiology A Latent Spatial Factor Approach for Synthesizing Opioid-Associated Deaths and Treatment Admissions in Ohio ...
Epidemiology Humans Molecular Epidemiology Monte Carlo Method Mycobacterium Tuberculosis Netherlands Odds Ratio Research Risk ... 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 ...
... and other forms of bias were avoided. We strongly recommend all papers reporting potential new biomarkers be evaluated by an ... Epidemiology. With COVID-19, modeling takes on life and death importance * Medicine/Diseases. Faucis straight talk ... including those that could be perceived as potential sources of bias. Patents (whether applications or awards to the authors or ...
The bias detective * Ecology. Can sentinel trees warn of devastating pests? * Asia/Pacific News. New mercury compound spotted ... Epidemiology. With COVID-19, modeling takes on life and death importance * Medicine/Diseases. Faucis straight talk ...
The search strategy appeared to include some relevant sources and efforts were made to minimise language bias. However, the ... Angiography, Digital Subtraction /instrumentation; Arterial Occlusive Diseases /radiography; Confounding Factors (Epidemiology ... Publication bias was examined in a funnel plot and by Eggers regression test. ... The review process was carried out with good measures to minimise errors and bias throughout. The authors acknowledge several ...
Threats to Validity: Confounding and Bias. Epidemiology Post-Test. PART TWO: EVIDENCE-BASED MEDICINE. Introduction: Definitions ... PART ONE: EPIDEMIOLOGY. Epidemiology Pre-Test. Introduction: History of Epidemiology. Concepts in Infectious Disease ... Injury Control - Disaster Preparedness - Epidemiology. Workshop Structure. in addition to the lectures on epidemiology and ... Texts: The last time I counted, there were well over 50 introductory and intermediate epidemiology texts in print. There is no ...
Observational studiesModern EpidemiologyPotential biasesDictionary of EpidemiologyTime-Related BiasesInferenceConfoundingMethodologyPrevalence estimatesRecallInfectious Disease EpidemiologyPopulationsClinicalEpidemiological researchCardiovascularInferencesMethodologicalStudyAssessmentDescriptiveIntermediate epidemiologyEstimates2016ColliderCONCLUSIONSStatisticalOutcomePublication biasJournalSelectionAttrition biasPrinciplesGordisImmortal time biasRefersInterventionsMagnitudeLess biased
- Metformin and the Risk of Cancer: Time-Related Biases in Observational Studies. (diabetesjournals.org)
- However, a careful assessment of the observational studies conducted to date point to some important time-related biases that systematically exaggerated the reported antitumor effects of metformin ( 10 ). (diabetesjournals.org)
- 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. (sportsci.org)
- 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. (sportsci.org)
- In observational studies of the effect of statin therapy on cardiovascular outcomes, healthy user bias and confounding by indication are most likely present, though many other sources of bias may also exist. (biomedcentral.com)
- Controlled laboratory experiments and randomized clinical trials are less prone to bias than are observational studies such as cohort or case-control studies, but this protection is only available for a limited set of conclusions, and bias must be addressed in all studies. (encyclopedia.com)
- These powerful techniques are absolutely necessary in analyzing observational studies and can be used to "mop up" some bias in designed experiments, but their effectiveness depends on model validity and expert tuning to the specific study. (encyclopedia.com)
- Modern Epidemiology (Third ed. (wikipedia.org)
- Sharyn Orton, Ph.D. American Red Cross, Rockville, MD Suggested reading: Modern Infectious Disease Epidemiology (1994) by Johan Giesecke Modern Epidemiology (1998) by Kenneth Rothman and Sander Greenland. (slideserve.com)
- Modern Epidemiology, 2nd edition. (encyclopedia.com)
- Because of the difficulties in achieving high response rates and the potential biases resulting from self-selection, understanding the reasons for non-response and the application of methods for limiting non-response is indispensible. (isciii.es)
- Potential biases in machine learning algorithms using electronic health record data. (ahrq.gov)
- We will close the course by revisiting causal inference in epidemiology, discussing how we can go through all potential explanations of an association before deciding whether it is of causal nature. (coursera.org)
- 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. (bu.edu)
- 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. (cdc.gov)
- We will also briefly discuss about the Directed Acyclic Graphs, which is a novel way to detect bias and confounding and control for them. (coursera.org)
- Methods are presented for the assessment and control of confounding, misclassification bias, and selection bias. (bu.edu)
- 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. (unc.edu)
- who classified biases into three main classes: selection bias, information bias, and confounding 4 . (ispub.com)
- Unlike confounding bias, selection and information bias cannot be corrected or controlled for after the completion of a study 1 . (ispub.com)
- These studies have indicated that a substantial proportion of RCTs might be at high risk for confounding, selection and information biases because they were not designed optimally to minimize threats to internal validity. (biomedcentral.com)
- For example, the method of randomization was often not reported, so that it was not clear if the RCTs actually controlled for confounding by correct randomization, or concealment of random allocation was not described, which may have put the studies at risk for selection bias. (biomedcentral.com)
- 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. (biomedcentral.com)
- This material serves as brief overview and an introduction to the uses, methodology and clinical application of epidemiology. (columbia.edu)
- 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. (springer.com)
- Assessment of racial and ethnic bias in autism spectrum disorder prevalence estimates from a US surveillance system. (nih.gov)
- The importance of estimating selection bias on prevalence estimates, shortly after a disaster. (nivel.nl)
- 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. (cdc.gov)
- 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. (cdc.gov)
- 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. (cdc.gov)
- 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 ). (aacrjournals.org)
- Evidence for biased recall was presented. (unc.edu)
- Set in the Clinical Practice Research Datalink, in which electronic medical records are recorded prospectively, eliminating recall bias. (bmj.com)
- Recall bias in a case-control study of low birth weight. (biomedsearch.com)
- 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. (biomedsearch.com)
- To render it meaningful, "bias" must be linked to another word (such as selection bias, recall bias and publication bias). (etikkom.no)
- Recall bias represents a major threat to the internal validity of studies using self-reported data. (ispub.com)
- This pattern of recall errors can lead to differential misclassification of the related variable among study subjects with a subsequent distortion of measure of association in any direction from the null, depending on the magnitude and direction of the bias. (ispub.com)
- Although recall bias has largely been viewed as a common concern in case-control studies, it also has been documented as an issue in some prospective cohort and randomized controlled trial designs. (ispub.com)
- The aim of this paper is to address recall bias in selective studies employing retrospective and prospective designs and present some key methodological strategies to consider in analytic research using reported data in order to avoid or minimize recall bias. (ispub.com)
- Recall bias is a classic form of information bias 1 . (ispub.com)
- According to Sackett's catalog of biases in analytic research, recall bias can be introduced in the data collection stage of investigation 6 . (ispub.com)
- Recall bias of sufficient magnitude can depart the estimated measure of effect size either towards or away form the null, depending on the proportions of subjects misclassified. (ispub.com)
- Owing to data protection legislation and a great number of different health care insurance providers, the assessment of recall and non-response bias is challenging to impossible in many countries. (biomedcentral.com)
- Direct validation studies are needed to disentangle the impact of recall and non-response bias. (biomedcentral.com)
- However, given the above hurdles for linking individual survey data to administrative data and the prohibition on using non-responder data without consent, studies on the impact of recall and non-response bias are largely lacking. (biomedcentral.com)
- Other types of bias typically encountered in epidemiologic research, particularly those employing observational designs, include recall and observer bias. (encyclopedia.com)
- 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. (biomedcentral.com)
- 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. (biomedcentral.com)
- 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. (biomedcentral.com)
- 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 . (cambridge.org)
- 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. (cdc.gov)
- 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. (plos.org)
- 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. (plos.org)
- 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. (edu.au)
- The authors raise concern that implicit bias in the care that disadvantaged populations receive may influence algorithms, which will amplify this bias. (ahrq.gov)
- In this study we evaluated testing bias for neutrophil counts in clinical practice by using results from requested and non-requested hematological blood tests. (biomedcentral.com)
- The results from our study show the importance of evaluating testing bias in epidemiological studies obtaining data from clinical databases. (biomedcentral.com)
- Such selective processes might induce testing bias in clinical database studies. (biomedcentral.com)
- 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. (biomedcentral.com)
- Requesting neutrophil counts specifically for certain diseases or for glucocorticoid users might cause testing bias in clinical databases. (biomedcentral.com)
- The association between traditional cardiovascular risk factors and an adverse clinical outcome in CHF patients is referred to as "reverse epidemiology. (onlinejacc.org)
- 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. (springer.com)
- Is omission of free text records a possible source of data loss and bias in Clinical Practice Research Datalink studies? (bmj.com)
- Objectives To estimate data loss and bias in studies of Clinical Practice Research Datalink (CPRD) data that restrict analyses to Read codes, omitting anything recorded as text. (bmj.com)
- A Clinical Trial with Combined Transcranial Direct Current Stimulation and Attentional Bias Modification in Alcohol Dependent Patients. (bioportfolio.com)
- Publication bias has an impact on the interpretation of clinical trials and meta-analyses. (bioportfolio.com)
- This unit introduces the concept of clinical epidemiology and provides students with core skills in clinical epidemiology at an introductory level. (edu.au)
- 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. (etikkom.no)
- However, such a comparison risks healthy adherer bias because higher adherence may correlate with a healthier lifestyle and higher adherence to other cardiovascular drugs. (biomedcentral.com)
- The aim of this study is to investigate the role of bias in an assessment of the effect of adherence to statin therapy on cardiovascular & cerebrovascular mortality among statin users in the Netherlands over the period 1994 to 2010. (biomedcentral.com)
- 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. (etikkom.no)
- Bias is defined as deviation of results or inferences from the truth, or processes leading to such deviation 1 . (ispub.com)
- 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. (mendeley.com)
- 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. (rti.org)
- Among women, a modest change in reporting bias was observed for a small number of experiences, possibly due to changes in participation, social acceptability and methodological differences between surveys. (bmj.com)
- A study can yield biased results for many different reasons. (coursera.org)
- In this course you will learn about the main types of bias and what effect they might have on your study findings. (coursera.org)
- In epidemiology, a countable instance in the population or study group of a particular disease, health disorder, or condition under investigation. (cdc.gov)
- 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. (bu.edu)
- 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). (cambridge.org)
- 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. (bmj.com)
- 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. (mendeley.com)
- 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. (transtutors.com)
- 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. (clinicaltrials.gov)
- The concept of immortal time bias is depicted schematically using the cohort study from the Taiwanese National Health Insurance data during 2000-2007: 12,005 patients who received at least two prescriptions of metformin were compared with 4,597 patients who received one prescription of another oral agent during this period ( 15 ). (diabetesjournals.org)
- 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. (bioportfolio.com)
- 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. (bioportfolio.com)
- Evaluation of non-response bias in a cohort study of World Trade Center terrorist attack survivors. (cdc.gov)
- 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). (etikkom.no)
- 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. (etikkom.no)
- 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. (etikkom.no)
- The phenomenon of selection bias encompasses more than skewness in the selection of the study population (Odierna DH et al. (etikkom.no)
- This module will provide students with foundations of epidemiology, including basic concepts underpinning study design, how to pose an answerable question and to design a study to answer said question. (ljmu.ac.uk)
- The present study was conducted to assess possible selection bias of participants in the IDEFICS health survey by comparing the socioeconomic, demographic, and anthropometric characteristics of the study population to an unselected reference population. (biomedcentral.com)
- One way to avoid this bias is to study only patients with severe symptoms, who would always be referred for work-up, so that diagnostic suspicion bias should play no role. (annals.org)
- Such bias results from systematic, nonrandom effects that, even in a large study, produce an incorrect answer or result by weakening, distorting, or spuriously creating a relation between a risk factor or intervention and the observed outcome. (encyclopedia.com)
- There are many types of bias, which can be intentional or unintentional, and events or features that bias one study may have no biasing effect on another. (encyclopedia.com)
- For an interesting example of bias consider a study of the effects of coaching on SAT scores, reporting that students completing the coaching program averaged a fifty-point-higher score on their next SAT exam than those who dropped out. (encyclopedia.com)
- Epidemiology (derived from Greek epi "on, upon", demos "people", logos "study") is a scientific discipline studying the distribution of diseases in a population (descriptive epidemiology ) and the factors influencing this distribution (analytical epidemiology ). (bfs.de)
- CONCLUSION: Risk-of-bias assessment remains a challenging but essential step in systematic reviews. (rti.org)
- Risk of bias assessment: (9) Application of the risk of bias assessment results. (bioportfolio.com)
- In this last paper of the series about risk of bias assessment, we introduce the application of risk of bias assessment results. (bioportfolio.com)
- Risk of bias assessment is one of the key steps in the assessment of qu. (bioportfolio.com)
- There is no sense of prejudice or subjectivity implied in the assessment of bias under these conditions. (bioportfolio.com)
- Direct assessment of non-response bias is only feasible if administrative data from both, survey participants and non-responders are available. (biomedcentral.com)
- Untrustworthy treatment comparisons are those in which biases, or the play of chance, or both result in misleading estimates of the effects of treatments. (jameslindlibrary.org)
- We compared estimates for outcomes that occurred before Natsal-2 and expected these to be consistent between surveys if no change in reporting bias had occurred. (bmj.com)
- 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. (lww.com)
- It can be shown that selecting a sample of patients with heart failure induces collider stratification bias in the estimated effect of obesity on death in an analysis that does not adequately control for the unmeasured factors 6 -although such bias is not necessarily large. (lww.com)
- Can collider bias explain paradoxical associations? (uio.no)
- 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 . (columbia.edu)
- Minimizing bias in design and conduct is preferable to relying on post hoc statistical "cures" such as covariance of adjustment and causal modeling. (encyclopedia.com)
- 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). (mendeley.com)
- It must be noted that such a difference in response will not lead to a bias as long as it is not also associated with a systematic difference in outcome between the two response groups. (transtutors.com)
- 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. (rti.org)
- Tackling the outcome bias related to the effectiveness of antibiotics against the common cold: results of a randomized controlled trial applying the Solomon four-group design. (bioportfolio.com)
- 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 (www.tidsskriftet.no). (etikkom.no)
- The Internet Journal of Epidemiology. (ispub.com)
- 7 In a recent issue of Journal of Epidemiology and Community Health Rychetnik et al moved the debate forward by seeking to broaden the scope of the criteria that are used to appraise public health interventions. (bmj.com)
- Commentary: Selection Bias as an Explanation for the Obesit. (lww.com)
- This is a special form of selection bias 4 and could arise as follows. (lww.com)
- The occurrence of information biases may not be independent of the occurrence of selection biases. (wikipedia.org)
- The reasons for this important discrepancy, including the possibility of a selection bias favoring men, should be further investigated. (iit.edu)
- What is Selection Bias? (transtutors.com)
- Selection Bias occurs when the data selected as a sample is not random enough. (transtutors.com)
- The result obtained from a sample that suffers selection bias does not reflect the correct conclusion. (transtutors.com)
- The presence of selection bias results in false results. (transtutors.com)
- There are many cases where selection bias can occur. (transtutors.com)
- 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. (transtutors.com)
- 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. (transtutors.com)
- Sampling bias is another type of selection bias. (transtutors.com)
- Time scale can also lead to selection bias. (transtutors.com)
- In such cases the chances that the sample is not representative of the population (selection bias) is very high. (transtutors.com)
- 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. (transtutors.com)
- Though the concepts of selection bias and self-selecting bias appear to be similar they are caused by different reasons. (transtutors.com)
- 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). (transtutors.com)
- However, they are more sensitive to selection bias. (transtutors.com)
- Most recently, she used instrumental variable techniques to correct for selection bias due survey non-participation in estimating HIV prevalence in Zambia and Botswana. (harvard.edu)
- Exploring selection bias by causal frailty models: The magnitude matters. (uio.no)
- What is Attrition Bias? (transtutors.com)
- An example of attrition bias is a test done by a shampoo company, regarding the effectiveness of the new product (anti-hair fall shampoo). (transtutors.com)
- 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. (transtutors.com)
- attrition bias etc. (etikkom.no)
- 09-SelectionBias - Principles of Epidemiology for Public. (coursehero.com)
- 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. (worldcat.org)
- 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. (worldcat.org)