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.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.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.Genetic Predisposition to Disease: A latent susceptibility to disease at the genetic level, which may be activated under certain conditions.Polymorphism, Single Nucleotide: A single nucleotide variation in a genetic sequence that occurs at appreciable frequency in the population.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.Genotype: The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.Asia, Western: The geographical designation for the countries of the MIDDLE EAST and the countries BANGLADESH; BHUTAN; INDIA; NEPAL; PAKISTAN; and SRI LANKA. (From Random House Unabridged Dictionary, 2d ed, 1993 & Webster's New Geographical Dictionary, 1988)Polymorphism, Genetic: The regular and simultaneous occurrence in a single interbreeding population of two or more discontinuous genotypes. The concept includes differences in genotypes ranging in size from a single nucleotide site (POLYMORPHISM, SINGLE NUCLEOTIDE) to large nucleotide sequences visible at a chromosomal level.Ethiopia: An independent state in eastern Africa. Ethiopia is located in the Horn of Africa and is bordered on the north and northeast by Eritrea, on the east by Djibouti and Somalia, on the south by Kenya, and on the west and southwest by Sudan. Its capital is Addis Ababa.Gene Frequency: The proportion of one particular in the total of all ALLELES for one genetic locus in a breeding POPULATION.IndiaRetrospective 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.Haplotypes: The genetic constitution of individuals with respect to one member of a pair of allelic genes, or sets of genes that are closely linked and tend to be inherited together such as those of the MAJOR HISTOCOMPATIBILITY COMPLEX.Smoking: Inhaling and exhaling the smoke of burning TOBACCO.Extraction, Obstetrical: Extraction of the fetus by means of obstetrical instruments.Risk: The probability that an event will occur. It encompasses a variety of measures of the probability of a generally unfavorable outcome.Malaysia: A parliamentary democracy with a constitutional monarch in southeast Asia, consisting of 11 states (West Malaysia) on the Malay Peninsula and two states (East Malaysia) on the island of BORNEO. It is also called the Federation of Malaysia. Its capital is Kuala Lumpur. Before 1963 it was the Union of Malaya. It reorganized in 1948 as the Federation of Malaya, becoming independent from British Malaya in 1957 and becoming Malaysia in 1963 as a federation of Malaya, Sabah, Sarawak, and Singapore (which seceded in 1965). The form Malay- probably derives from the Tamil malay, mountain, with reference to its geography. (From Webster's New Geographical Dictionary, 1988, p715 & Room, Brewer's Dictionary of Names, 1992, p329)Pregnancy: The status during which female mammals carry their developing young (EMBRYOS or FETUSES) in utero before birth, beginning from FERTILIZATION to BIRTH.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.NepalAge 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.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.Alleles: Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.China: A country spanning from central Asia to the Pacific Ocean.Matched-Pair Analysis: A type of analysis in which subjects in a study group and a comparison group are made comparable with respect to extraneous factors by individually pairing study subjects with the comparison group subjects (e.g., age-matched controls).Diarrhea, Infantile: DIARRHEA occurring in infants from newborn to 24-months old.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.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)Infant, Newborn: An infant during the first month after birth.Biological Markers: Measurable and quantifiable biological parameters (e.g., specific enzyme concentration, specific hormone concentration, specific gene phenotype distribution in a population, presence of biological substances) which serve as indices for health- and physiology-related assessments, such as disease risk, psychiatric disorders, environmental exposure and its effects, disease diagnosis, metabolic processes, substance abuse, pregnancy, cell line development, epidemiologic studies, etc.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.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.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.Linkage Disequilibrium: Nonrandom association of linked genes. This is the tendency of the alleles of two separate but already linked loci to be found together more frequently than would be expected by chance alone.ItalyCohort 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.Severity of Illness Index: Levels within a diagnostic group which are established by various measurement criteria applied to the seriousness of a patient's disorder.Genetic Association Studies: The analysis of a sequence such as a region of a chromosome, a haplotype, a gene, or an allele for its involvement in controlling the phenotype of a specific trait, metabolic pathway, or disease.Chi-Square Distribution: A distribution in which a variable is distributed like the sum of the squares of any given independent random variable, each of which has a normal distribution with mean of zero and variance of one. The chi-square test is a statistical test based on comparison of a test statistic to a chi-square distribution. The oldest of these tests are used to detect whether two or more population distributions differ from one another.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.TurkeyAge 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.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.Patient Dropouts: Discontinuance of care received by patient(s) due to reasons other than full recovery from the disease.Delivery, Obstetric: Delivery of the FETUS and PLACENTA under the care of an obstetrician or a health worker. Obstetric deliveries may involve physical, psychological, medical, or surgical interventions.Parity: The number of offspring a female has borne. It is contrasted with GRAVIDITY, which refers to the number of pregnancies, regardless of outcome.Disease Outbreaks: Sudden increase in the incidence of a disease. The concept includes EPIDEMICS and PANDEMICS.Great BritainAsian Continental Ancestry Group: Individuals whose ancestral origins are in the southeastern and eastern areas of the Asian continent.PakistanAbortion, Spontaneous: Expulsion of the product of FERTILIZATION before completing the term of GESTATION and without deliberate interference.Rural Population: The inhabitants of rural areas or of small towns classified as rural.Crohn Disease: A chronic transmural inflammation that may involve any part of the DIGESTIVE TRACT from MOUTH to ANUS, mostly found in the ILEUM, the CECUM, and the COLON. In Crohn disease, the inflammation, extending through the intestinal wall from the MUCOSA to the serosa, is characteristically asymmetric and segmental. Epithelioid GRANULOMAS may be seen in some patients.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.Time Factors: Elements of limited time intervals, contributing to particular results or situations.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.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.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.GermanyArylamine N-Acetyltransferase: An enzyme that catalyzes the transfer of acetyl groups from ACETYL-COA to arylamines. It can also catalyze acetyl transfer between arylamines without COENZYME A and has a wide specificity for aromatic amines, including SEROTONIN. However, arylamine N-acetyltransferase should not be confused with the enzyme ARYLALKYLAMINE N-ACETYLTRANSFERASE which is also referred to as SEROTONIN ACETYLTRANSFERASE.Reference Values: The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.Breast Neoplasms: Tumors or cancer of the human BREAST.Colitis, Ulcerative: Inflammation of the COLON that is predominantly confined to the MUCOSA. Its major symptoms include DIARRHEA, rectal BLEEDING, the passage of MUCUS, and ABDOMINAL PAIN.Epidemiologic Methods: Research techniques that focus on study designs and data gathering methods in human and animal populations.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.Occupational Exposure: The exposure to potentially harmful chemical, physical, or biological agents that occurs as a result of one's occupation.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.IranAnalysis of Variance: A statistical technique that isolates and assesses the contributions of categorical independent variables to variation in the mean of a continuous dependent variable.Colorectal Neoplasms: Tumors or cancer of the COLON or the RECTUM or both. Risk factors for colorectal cancer include chronic ULCERATIVE COLITIS; FAMILIAL POLYPOSIS COLI; exposure to ASBESTOS; and irradiation of the CERVIX UTERI.Adenoma: A benign epithelial tumor with a glandular organization.Genome-Wide Association Study: An analysis comparing the allele frequencies of all available (or a whole GENOME representative set of) polymorphic markers in unrelated patients with a specific symptom or disease condition, and those of healthy controls to identify markers associated with a specific disease or condition.Pregnancy Complications: Conditions or pathological processes associated with pregnancy. They can occur during or after pregnancy, and range from minor discomforts to serious diseases that require medical interventions. They include diseases in pregnant females, and pregnancies in females with diseases.Diabetes Mellitus, Type 2: A subclass of DIABETES MELLITUS that is not INSULIN-responsive or dependent (NIDDM). It is characterized initially by INSULIN RESISTANCE and HYPERINSULINEMIA; and eventually by GLUCOSE INTOLERANCE; HYPERGLYCEMIA; and overt diabetes. Type II diabetes mellitus is no longer considered a disease exclusively found in adults. Patients seldom develop KETOSIS but often exhibit OBESITY.Travel: Aspects of health and disease related to travel.Body Mass Index: An indicator of body density as determined by the relationship of BODY WEIGHT to BODY HEIGHT. BMI=weight (kg)/height squared (m2). BMI correlates with body fat (ADIPOSE TISSUE). Their relationship varies with age and gender. For adults, BMI falls into these categories: below 18.5 (underweight); 18.5-24.9 (normal); 25.0-29.9 (overweight); 30.0 and above (obese). (National Center for Health Statistics, Centers for Disease Control and Prevention)ROC Curve: A graphic means for assessing the ability of a screening test to discriminate between healthy and diseased persons; may also be used in other studies, e.g., distinguishing stimuli responses as to a faint stimuli or nonstimuli.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.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.Socioeconomic Factors: Social and economic factors that characterize the individual or group within the social structure.Breast Feeding: The nursing of an infant at the breast.EnglandOccupational Diseases: Diseases caused by factors involved in one's employment.Pre-Eclampsia: A complication of PREGNANCY, characterized by a complex of symptoms including maternal HYPERTENSION and PROTEINURIA with or without pathological EDEMA. Symptoms may range between mild and severe. Pre-eclampsia usually occurs after the 20th week of gestation, but may develop before this time in the presence of trophoblastic disease.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.TaiwanFamily Health: The health status of the family as a unit including the impact of the health of one member of the family on the family as a unit and on individual family members; also, the impact of family organization or disorganization on the health status of its members.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)Diet: Regular course of eating and drinking adopted by a person or animal.Colonoscopy: Endoscopic examination, therapy or surgery of the luminal surface of the colon.Lung Neoplasms: Tumors or cancer of the LUNG.Venous Thrombosis: The formation or presence of a blood clot (THROMBUS) within a vein.Homozygote: An individual in which both alleles at a given locus are identical.Alcohol Drinking: Behaviors associated with the ingesting of alcoholic beverages, including social drinking.Stomach Neoplasms: Tumors or cancer of the STOMACH.Fractures, Bone: Breaks in bones.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)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.Spain: Parliamentary democracy located between France on the northeast and Portugual on the west and bordered by the Atlantic Ocean and the Mediterranean Sea.Postmenopause: The physiological period following the MENOPAUSE, the permanent cessation of the menstrual life.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.European Continental Ancestry Group: Individuals whose ancestral origins are in the continent of Europe.Esophageal Neoplasms: Tumors or cancer of the ESOPHAGUS.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.Hypertension: Persistently high systemic arterial BLOOD PRESSURE. Based on multiple readings (BLOOD PRESSURE DETERMINATION), hypertension is currently defined as when SYSTOLIC PRESSURE is consistently greater than 140 mm Hg or when DIASTOLIC PRESSURE is consistently 90 mm Hg or more.Educational Status: Educational attainment or level of education of individuals.Predictive Value of Tests: In screening and diagnostic tests, the probability that a person with a positive test is a true positive (i.e., has the disease), is referred to as the predictive value of a positive test; whereas, the predictive value of a negative test is the probability that the person with a negative test does not have the disease. Predictive value is related to the sensitivity and specificity of the test.JapanGenetic Markers: A phenotypically recognizable genetic trait which can be used to identify a genetic locus, a linkage group, or a recombination event.Pilot Projects: Small-scale tests of methods and procedures to be used on a larger scale if the pilot study demonstrates that these methods and procedures can work.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)SwedenGenetic Variation: Genotypic differences observed among individuals in a population.Adenocarcinoma: A malignant epithelial tumor with a glandular organization.Hemoglobin A, Glycosylated: Minor hemoglobin components of human erythrocytes designated A1a, A1b, and A1c. Hemoglobin A1c is most important since its sugar moiety is glucose covalently bound to the terminal amino acid of the beta chain. Since normal glycohemoglobin concentrations exclude marked blood glucose fluctuations over the preceding three to four weeks, the concentration of glycosylated hemoglobin A is a more reliable index of the blood sugar average over a long period of time.Hospitalization: The confinement of a patient in a hospital.Schizophrenia: A severe emotional disorder of psychotic depth characteristically marked by a retreat from reality with delusion formation, HALLUCINATIONS, emotional disharmony, and regressive behavior.Carcinoma, Squamous Cell: A carcinoma derived from stratified SQUAMOUS EPITHELIAL CELLS. It may also occur in sites where glandular or columnar epithelium is normally present. (From Stedman, 25th ed)Tuberculosis, Pulmonary: MYCOBACTERIUM infections of the lung.Helicobacter Infections: Infections with organisms of the genus HELICOBACTER, particularly, in humans, HELICOBACTER PYLORI. The clinical manifestations are focused in the stomach, usually the gastric mucosa and antrum, and the upper duodenum. This infection plays a major role in the pathogenesis of type B gastritis and peptic ulcer disease.Diabetes Complications: Conditions or pathological processes associated with the disease of diabetes mellitus. Due to the impaired control of BLOOD GLUCOSE level in diabetic patients, pathological processes develop in numerous tissues and organs including the EYE, the KIDNEY, the BLOOD VESSELS, and the NERVE TISSUE.Patient Acceptance of Health Care: The seeking and acceptance by patients of health service.Helicobacter pylori: A spiral bacterium active as a human gastric pathogen. It is a gram-negative, urease-positive, curved or slightly spiral organism initially isolated in 1982 from patients with lesions of gastritis or peptic ulcers in Western Australia. Helicobacter pylori was originally classified in the genus CAMPYLOBACTER, but RNA sequencing, cellular fatty acid profiles, growth patterns, and other taxonomic characteristics indicate that the micro-organism should be included in the genus HELICOBACTER. It has been officially transferred to Helicobacter gen. nov. (see Int J Syst Bacteriol 1989 Oct;39(4):297-405).Blood Glucose: Glucose in blood.Obesity: A status with BODY WEIGHT that is grossly above the acceptable or desirable weight, usually due to accumulation of excess FATS in the body. The standards may vary with age, sex, genetic or cultural background. In the BODY MASS INDEX, a BMI greater than 30.0 kg/m2 is considered obese, and a BMI greater than 40.0 kg/m2 is considered morbidly obese (MORBID OBESITY).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.Social Class: A stratum of people with similar position and prestige; includes social stratification. Social class is measured by criteria such as education, occupation, and income.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.Quality Control: A system for verifying and maintaining a desired level of quality in a product or process by careful planning, use of proper equipment, continued inspection, and corrective action as required. (Random House Unabridged Dictionary, 2d ed)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.Enzyme-Linked Immunosorbent Assay: An immunoassay utilizing an antibody labeled with an enzyme marker such as horseradish peroxidase. While either the enzyme or the antibody is bound to an immunosorbent substrate, they both retain their biologic activity; the change in enzyme activity as a result of the enzyme-antibody-antigen reaction is proportional to the concentration of the antigen and can be measured spectrophotometrically or with the naked eye. Many variations of the method have been developed.Coronary Artery Disease: Pathological processes of CORONARY ARTERIES that may derive from a congenital abnormality, atherosclerotic, or non-atherosclerotic cause.Registries: The systems and processes involved in the establishment, support, management, and operation of registers, e.g., disease registers.Liver Neoplasms: Tumors or cancer of the LIVER.Postoperative Complications: Pathologic processes that affect patients after a surgical procedure. They may or may not be related to the disease for which the surgery was done, and they may or may not be direct results of the surgery.Disease Progression: The worsening of a disease over time. This concept is most often used for chronic and incurable diseases where the stage of the disease is an important determinant of therapy and prognosis.Magnetic Resonance Imaging: Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.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).Neoplasm Staging: Methods which attempt to express in replicable terms the extent of the neoplasm in the patient.Promoter Regions, Genetic: DNA sequences which are recognized (directly or indirectly) and bound by a DNA-dependent RNA polymerase during the initiation of transcription. Highly conserved sequences within the promoter include the Pribnow box in bacteria and the TATA BOX in eukaryotes.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.Glutathione S-Transferase pi: A glutathione transferase that catalyzes the conjugation of electrophilic substrates to GLUTATHIONE. This enzyme has been shown to provide cellular protection against redox-mediated damage by FREE RADICALS.Crowding: An excessive number of individuals, human or animal, in relation to available space.Tumor Markers, Biological: Molecular products metabolized and secreted by neoplastic tissue and characterized biochemically in cells or body fluids. They are indicators of tumor stage and grade as well as useful for monitoring responses to treatment and predicting recurrence. Many chemical groups are represented including hormones, antigens, amino and nucleic acids, enzymes, polyamines, and specific cell membrane proteins and lipids.Stroke: A group of pathological conditions characterized by sudden, non-convulsive loss of neurological function due to BRAIN ISCHEMIA or INTRACRANIAL HEMORRHAGES. Stroke is classified by the type of tissue NECROSIS, such as the anatomic location, vasculature involved, etiology, age of the affected individual, and hemorrhagic vs. non-hemorrhagic nature. (From Adams et al., Principles of Neurology, 6th ed, pp777-810)Diabetes Mellitus, Type 1: A subtype of DIABETES MELLITUS that is characterized by INSULIN deficiency. It is manifested by the sudden onset of severe HYPERGLYCEMIA, rapid progression to DIABETIC KETOACIDOSIS, and DEATH unless treated with insulin. The disease may occur at any age, but is most common in childhood or adolescence.Methylenetetrahydrofolate Reductase (NADPH2): A flavoprotein amine oxidoreductase that catalyzes the reversible conversion of 5-methyltetrahydrofolate to 5,10-methylenetetrahydrofolate. This enzyme was formerly classified as EC 1.1.1.171.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.Phenotype: The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.Models, 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.Anti-Inflammatory Agents, Non-Steroidal: Anti-inflammatory agents that are non-steroidal in nature. In addition to anti-inflammatory actions, they have analgesic, antipyretic, and platelet-inhibitory actions.They act by blocking the synthesis of prostaglandins by inhibiting cyclooxygenase, which converts arachidonic acid to cyclic endoperoxides, precursors of prostaglandins. Inhibition of prostaglandin synthesis accounts for their analgesic, antipyretic, and platelet-inhibitory actions; other mechanisms may contribute to their anti-inflammatory effects.Australia: The smallest continent and an independent country, comprising six states and two territories. Its capital is Canberra.Feces: Excrement from the INTESTINES, containing unabsorbed solids, waste products, secretions, and BACTERIA of the DIGESTIVE SYSTEM.Statistics, Nonparametric: A class of statistical methods applicable to a large set of probability distributions used to test for correlation, location, independence, etc. In most nonparametric statistical tests, the original scores or observations are replaced by another variable containing less information. An important class of nonparametric tests employs the ordinal properties of the data. Another class of tests uses information about whether an observation is above or below some fixed value such as the median, and a third class is based on the frequency of the occurrence of runs in the data. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed, p1284; Corsini, Concise Encyclopedia of Psychology, 1987, p764-5)Statistics 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.Urban Population: The inhabitants of a city or town, including metropolitan areas and suburban areas.Sepsis: Systemic inflammatory response syndrome with a proven or suspected infectious etiology. When sepsis is associated with organ dysfunction distant from the site of infection, it is called severe sepsis. When sepsis is accompanied by HYPOTENSION despite adequate fluid infusion, it is called SEPTIC SHOCK.Ventilators, Mechanical: Mechanical devices used to produce or assist pulmonary ventilation.IrelandRecurrence: The return of a sign, symptom, or disease after a remission.Hypertension, Pregnancy-Induced: A condition in pregnant women with elevated systolic (>140 mm Hg) and diastolic (>90 mm Hg) blood pressure on at least two occasions 6 h apart. HYPERTENSION complicates 8-10% of all pregnancies, generally after 20 weeks of gestation. Gestational hypertension can be divided into several broad categories according to the complexity and associated symptoms, such as EDEMA; PROTEINURIA; SEIZURES; abnormalities in BLOOD COAGULATION and liver functions.African Americans: Persons living in the United States having origins in any of the black groups of Africa.Diseases in Twins: Disorders affecting TWINS, one or both, at any age.Multicenter Studies as Topic: Works about controlled studies which are planned and carried out by several cooperating institutions to assess certain variables and outcomes in specific patient populations, for example, a multicenter study of congenital anomalies in children.Sri LankaGenetic Loci: Specific regions that are mapped within a GENOME. Genetic loci are usually identified with a shorthand notation that indicates the chromosome number and the position of a specific band along the P or Q arm of the chromosome where they are found. For example the locus 6p21 is found within band 21 of the P-arm of CHROMOSOME 6. Many well known genetic loci are also known by common names that are associated with a genetic function or HEREDITARY DISEASE.Metabolic Syndrome X: A cluster of metabolic risk factors for CARDIOVASCULAR DISEASES and TYPE 2 DIABETES MELLITUS. The major components of metabolic syndrome X include excess ABDOMINAL FAT; atherogenic DYSLIPIDEMIA; HYPERTENSION; HYPERGLYCEMIA; INSULIN RESISTANCE; a proinflammatory state; and a prothrombotic (THROMBOSIS) state. (from AHA/NHLBI/ADA Conference Proceedings, Circulation 2004; 109:551-556)Genome, Human: The complete genetic complement contained in the DNA of a set of CHROMOSOMES in a HUMAN. The length of the human genome is about 3 billion base pairs.Mass Screening: Organized periodic procedures performed on large groups of people for the purpose of detecting disease.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.Lipids: A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)Bipolar Disorder: A major affective disorder marked by severe mood swings (manic or major depressive episodes) and a tendency to remission and recurrence.Epistasis, Genetic: A form of gene interaction whereby the expression of one gene interferes with or masks the expression of a different gene or genes. Genes whose expression interferes with or masks the effects of other genes are said to be epistatic to the effected genes. Genes whose expression is affected (blocked or masked) are hypostatic to the interfering genes.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.Fatigue Syndrome, Chronic: A syndrome characterized by persistent or recurrent fatigue, diffuse musculoskeletal pain, sleep disturbances, and subjective cognitive impairment of 6 months duration or longer. Symptoms are not caused by ongoing exertion; are not relieved by rest; and result in a substantial reduction of previous levels of occupational, educational, social, or personal activities. Minor alterations of immune, neuroendocrine, and autonomic function may be associated with this syndrome. There is also considerable overlap between this condition and FIBROMYALGIA. (From Semin Neurol 1998;18(2):237-42; Ann Intern Med 1994 Dec 15;121(12): 953-9)Insulin: A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1).Asthma: A form of bronchial disorder with three distinct components: airway hyper-responsiveness (RESPIRATORY HYPERSENSITIVITY), airway INFLAMMATION, and intermittent AIRWAY OBSTRUCTION. It is characterized by spasmodic contraction of airway smooth muscle, WHEEZING, and dyspnea (DYSPNEA, PAROXYSMAL).Sudden Infant Death: The abrupt and unexplained death of an apparently healthy infant under one year of age, remaining unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene, and review of the clinical history. (Pediatr Pathol 1991 Sep-Oct;11(5):677-84)BrazilC-Reactive Protein: A plasma protein that circulates in increased amounts during inflammation and after tissue damage.Acute Disease: Disease having a short and relatively severe course.Prostatic Neoplasms: Tumors or cancer of the PROSTATE.Twins, Monozygotic: Two off-spring from the same PREGNANCY. They are from a single fertilized OVUM that split into two EMBRYOS. Such twins are usually genetically identical and of the same sex.Cholelithiasis: Presence or formation of GALLSTONES in the BILIARY TRACT, usually in the gallbladder (CHOLECYSTOLITHIASIS) or the common bile duct (CHOLEDOCHOLITHIASIS).Data Interpretation, Statistical: Application of statistical procedures to analyze specific observed or assumed facts from a particular study.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.Cardiovascular Diseases: Pathological conditions involving the CARDIOVASCULAR SYSTEM including the HEART; the BLOOD VESSELS; or the PERICARDIUM.Morbidity: The proportion of patients with a particular disease during a given year per given unit of population.Chromosomes, Human, Pair 5: One of the two pairs of human chromosomes in the group B class (CHROMOSOMES, HUMAN, 4-5).Hypoglycemia: A syndrome of abnormally low BLOOD GLUCOSE level. Clinical hypoglycemia has diverse etiologies. Severe hypoglycemia eventually lead to glucose deprivation of the CENTRAL NERVOUS SYSTEM resulting in HUNGER; SWEATING; PARESTHESIA; impaired mental function; SEIZURES; COMA; and even DEATH.Epinephrine: The active sympathomimetic hormone from the ADRENAL MEDULLA. It stimulates both the alpha- and beta- adrenergic systems, causes systemic VASOCONSTRICTION and gastrointestinal relaxation, stimulates the HEART, and dilates BRONCHI and cerebral vessels. It is used in ASTHMA and CARDIAC FAILURE and to delay absorption of local ANESTHETICS.Interviews as Topic: Conversations with an individual or individuals held in order to obtain information about their background and other personal biographical data, their attitudes and opinions, etc. It includes school admission or job interviews.Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.Coronary Disease: An imbalance between myocardial functional requirements and the capacity of the CORONARY VESSELS to supply sufficient blood flow. It is a form of MYOCARDIAL ISCHEMIA (insufficient blood supply to the heart muscle) caused by a decreased capacity of the coronary vessels.Pesticides: Chemicals used to destroy pests of any sort. The concept includes fungicides (FUNGICIDES, INDUSTRIAL); INSECTICIDES; RODENTICIDES; etc.Epidemiologic Studies: Studies designed to examine associations, commonly, hypothesized causal relations. They are usually concerned with identifying or measuring the effects of risk factors or exposures. The common types of analytic study are CASE-CONTROL STUDIES; COHORT STUDIES; and CROSS-SECTIONAL STUDIES.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.Chromosomes, Human, Pair 6: A specific pair GROUP C CHROMSOMES of the human chromosome classification.

Legalized physician-assisted suicide in Oregon--the first year's experience. (1/48039)

BACKGROUND AND METHODS: On October 27, 1997, Oregon legalized physician-assisted suicide. We collected data on all terminally ill Oregon residents who received prescriptions for lethal medications under the Oregon Death with Dignity Act and who died in 1998. The data were obtained from physicians' reports, death certificates, and interviews with physicians. We compared persons who took lethal medications prescribed under the act with those who died from similar illnesses but did not receive prescriptions for lethal medications. RESULTS: Information on 23 persons who received prescriptions for lethal medications was reported to the Oregon Health Division; 15 died after taking the lethal medications, 6 died from underlying illnesses, and 2 were alive as of January 1, 1999. The median age of the 15 patients who died after taking lethal medications was 69 years; 8 were male, and all 15 were white. Thirteen of the 15 patients had cancer. The case patients and controls were similar with regard to sex, race, urban or rural residence, level of education, health insurance coverage, and hospice enrollment. No case patients or controls expressed concern about the financial impact of their illness. One case patient and 15 controls expressed concern about inadequate control of pain (P=0.10). The case patients were more likely than the controls to have never married (P=0.04) and were more likely to be concerned about loss of autonomy due to illness (P=0.01) and loss of control of bodily functions (P=0.02). At death, 21 percent of the case patients and 84 percent of the controls were completely disabled (P<0.001). CONCLUSIONS: During the first year of legalized physician-assisted suicide in Oregon, the decision to request and use a prescription for lethal medication was associated with concern about loss of autonomy or control of bodily functions, not with fear of intractable pain or concern about financial loss. In addition, we found that the choice of physician-assisted suicide was not associated with level of education or health insurance coverage.  (+info)

Use of wood stoves and risk of cancers of the upper aero-digestive tract: a case-control study. (2/48039)

BACKGROUND: Incidence rates for cancers of the upper aero-digestive tract in Southern Brazil are among the highest in the world. A case-control study was designed to identify the main risk factors for carcinomas of mouth, pharynx, and larynx in the region. We tested the hypothesis of whether use of wood stoves is associated with these cancers. METHODS: Information on known and potential risk factors was obtained from interviews with 784 cases and 1568 non-cancer controls. We estimated the effect of use of wood stove by conditional logistic regression, with adjustment for smoking, alcohol consumption and for other sociodemographic and dietary variables chosen as empirical confounders based on a change-in-estimate criterion. RESULTS: After extensive adjustment for all the empirical confounders the odds ratio (OR) for all upper aero-digestive tract cancers was 2.68 (95% confidence interval [CI] : 2.2-3.3). Increased risks were also seen in site-specific analyses for mouth (OR = 2.73; 95% CI: 1.8-4.2), pharyngeal (OR = 3.82; 95% CI: 2.0-7.4), and laryngeal carcinomas (OR = 2.34; 95% CI: 1.2-4.7). Significant risk elevations remained for each of the three anatomic sites and for all sites combined even after we purposefully biased the analyses towards the null hypothesis by adjusting the effect of wood stove use only for positive empirical confounders. CONCLUSIONS: The association of use of wood stoves with cancers of the upper aero-digestive tract is genuine and unlikely to result from insufficient control of confounding. Due to its high prevalence, use of wood stoves may be linked to as many as 30% of all cancers occurring in the region.  (+info)

Hygiene behaviour in rural Nicaragua in relation to diarrhoea. (3/48039)

BACKGROUND: Childhood diarrhoea is a leading cause of morbidity and mortality in Nicaragua. Amongst the risk factors for its transmission are 'poor' hygiene practices. We investigated the effect of a large number of hygiene practices on diarrhoeal disease in children aged <2 years and validated the technique of direct observation of hygiene behaviour. METHODS: A prospective follow-up study was carried out in a rural zone of Nicaragua. From the database of a previously conducted case-control study on water and sanitation 172 families were recruited, half of which had experienced a higher than expected rate of diarrhoea in their children and the other half a lower rate. Hygiene behaviour was observed over two mornings and diarrhoea incidence was recorded with a calendar, filled out by the mother, and collected every week for 5 months. RESULTS: Of 46 'good' practices studied, 39 were associated with a lower risk of diarrhoea, five were unrelated and only for two a higher risk was observed. Washing of hands, domestic cleanliness (kitchen, living room, yard) and the use of a diaper/underclothes by the child had the strongest protective effect. Schooling (>3 years of primary school) and better economic position (possession of a radio) had a positive influence on general hygiene behaviour, education having a slightly stronger effect when a radio was present. Individual hygiene behaviour appeared to be highly variable in contrast with the consistent behaviour of the community as a whole. Feasible and appropriate indicators of hygiene behaviour were found to be domestic cleanliness and the use of a diaper or underclothes by the child. CONCLUSION: A consistent relationship between almost all hygiene practices and diarrhoea was detected, more schooling producing better hygiene behaviour. The high variability of hygiene behaviour at the individual level requires repeated observations (at least two) before and after the hygiene education in the event one wants to measure the impact of the campaign on the individual.  (+info)

Post-traumatic epilepsy: its complications and impact on occupational rehabilitation--an epidemiological study from India. (4/48039)

The objective of this study was to assess the prevalence of seizure disorder, neuropsychiatric disorders and reproductive outcome of employees with post-traumatic epilepsy (PTE) and their effect on occupational rehabilitation. A case-comparison group study design was used to compare 30 subjects with PTE with (1) 129 non-PTE and (2) 55 non-PTE matched control employees. The 55 non-PTE matched controls were selected from the 129 non-PTE employees on the basis of age, age at onset of seizure, age at marriage and length of employment. The PTE group had a lower fertility rate than the controls and more neuropsychiatric disorders and seizure disability. PTE employees were more occupationally rehabilitated than non-PTE employees (p = 0.033). Of the 30 PTE subjects, thirteen who were rehabilitated by placement had more seizure disability (p = 0.007) and a higher fertility rate (p = 0.018). High prevalence of seizure disability and increased fertility rate among the placed PTE employees suggested that there might be some association between severity of seizures and increased production of live offspring and work placement. Work suitability or placement should not be judged on clinical assessment only but psychosocial seizure assessment, disability evaluation and other psychometric tests which are of equal importance.  (+info)

Methodological issues in biomonitoring of low level exposure to benzene. (5/48039)

Data from a pilot study on unmetabolized benzene and trans,trans muconic acid (t,t-MA) excretion in filling station attendants and unexposed controls were used to afford methodological issues in the biomonitoring of low benzene exposures (around 0.1 ppm). Urinary concentrations of benzene and t,t-MA were measured by dynamic head-space capillary GC/FID and HPLC, respectively. The accuracy of the HPLC determination of t,t-MA was assessed in terms of inter- and intra-method reliability. The adequacy of urinary t,t-MA and benzene as biological markers of low benzene exposure was evaluated by analysing the relationship between personal exposure to benzene and biomarker excretion. Filling station attendants excreted significantly higher amounts of benzene, but not of t,t-MA, than controls. Adjusting for occupational benzene exposure, smokers excreted significantly higher amounts of t,t-MA, but not of unmetabolized benzene, than nonsmokers. A comparative analysis of the present and previously published biomonitoring surveys showed a good inter-study agreement regarding the amount of t,t-MA and unmetabolized benzene excreted (about 0.1-0.2 mg/l and 1-2 micrograms/l, respectively) per unit of exposure (0.1 ppm). For each biomarker, based on the distribution of parameters observed in the pilot study, we calculated the minimum sample size required to estimate the population mean with given confidence and precision.  (+info)

Post-shift changes in pulmonary function in a cement factory in eastern Saudi Arabia. (6/48039)

This cross-sectional study was conducted in 1992 in the oldest of three Portland cement producing factories in Eastern Saudi Arabia. The respirable dust level was in excess of the recommended ACGIH level in all sections. Spirometry was done for 149 cement workers and 348 controls, using a Vitalograph spirometer. FEV1, FVC, FEV1/FVC% and FEF25-75% were calculated and corrected to BTPS. A significantly higher post-shift reduction FEV1, FEV1/FVC% and FEF25-75% was observed in the exposed subjects. Multiple regression analysis showed a significant relationship between post-shift changes and exposure to cement dust but failed to support any relationship with smoking. These findings may indicate an increase in the bronchial muscle tone leading to some degree of bronchoconstriction as a result of an irritant effect induced by the acute exposure to cement dust.  (+info)

Alteration of circadian time structure of blood pressure caused by night shift schedule. (7/48039)

The effects of night shift schedules on circadian time structure of blood pressure were studied in seven healthy young subjects by continuous monitoring of blood pressure every 30 min for 72 h. In the control experiment, subjects were instructed to sleep at regular times with the light off at 00.00 h and the light on at 07.00 h. In the shift experiment, they were instructed to go to bed at 06.00 h and wake up at 11.00 h. The circadian rhythm of blood pressure rapidly phase delayed by 3.5 h in the second night shift day as a group phenomenon. Individual differences in changes in power spectral patterns of blood pressure were found in the night shift schedule. Ultradian rhythmicity of blood pressure was more pronounced in three subjects, whereas the circadian rhythmicity was maintained in four subjects. These findings held when the adaptation to shift work was taken into account.  (+info)

Relation between obesity and breast cancer in young women. (8/48039)

This study was conducted to assess the relation between body size and risk of breast cancer among young women. A case-control study was conducted among women aged 21-45 years living in three counties in Washington State. Cases were women born after 1944 with invasive or in situ breast cancer that was diagnosed between January 1, 1983, and April 30, 1990. Controls were selected using random digit dialing and were frequency-matched to cases on the basis of age and county of residence. Interviews took place between 1986 and 1992. Body size was evaluated using indices from several different time periods. After adjustment for confounders, a decreased risk of breast cancer was found for women in the highest quintile of body mass index (weight (kg)/height (m)2) as compared with the lowest quintile (for maximum lifetime body mass index, odds ratio = 0.69, 95% confidence interval (CI) 0.51-0.94). Age modified the relation between body size and risk of breast cancer. The odds ratio for women in the highest quintile of maximum body mass index who were aged 21-35 years was 0.29 (95% CI 0.16-0.55), as compared with an odds ratio of 1.5 for women aged 36-45 years (95% CI 0.9-2.5) (p for interaction = 0.003). This study supports prior research showing a decreased risk of breast cancer associated with increased body size among premenopausal or young women. More detailed analysis in this study found a strong effect that was limited to the youngest age group (< or = 35 years).  (+info)

  • Care must be taken to be objective in the search for past risk factors, especially since the outcome is already known, or the study may suffer from researcher bias. (cehjournal.org)
  • where α = alpha, β = 1 - power, ψ = odds ratio, n c is the continuity corrected sample size, m is the number of control subjects per case, and z p is the standard normal deviate for probability p. n is rounded up to the closest integer. (statsdirect.com)
  • For a more detailed account of design, conduct and analyses of epidemiological studies, the reader is referred to textbooks and methodological articles given in the list of references. (gfmer.ch)
  • Despite the substantial reduction in the number of new cases of Zika virus infection, it is important that preventive measures be drawn due to the high prevalence of Aedes aegypti mosquitoes in several areas and the possibility of recurrent waves of infection, as has been observed with other arboviruses in other locations. (biomedcentral.com)
  • The experimental approach allows control of the effect of extraneous factors that may have an effect on the outcome under study, but are not under investigation. (gfmer.ch)
  • Porta's Dictionary of Epidemiology defines the case-control study as: an observational epidemiological study of persons with the disease (or another outcome variable) of interest and a suitable control group of persons without the disease (comparison group, reference group). (wikipedia.org)
  • The evolution of resource allocation for prevention and control of TB in health department funding reflects the changing epidemiology of TB, new treatment guidelines, and the emergence of indicators to monitor program performance-all taking place in the context of flat funding for TB programs. (cdc.gov)
  • Third, editors and reviewers of epidemiology papers are too often dogmatic in their judgment of the potential for nonresponse bias in population-based studies. (lww.com)
  • 2018-02-15 The citation of this study may have changed due to the new version control system that has been implemented. (umich.edu)
  • A prospective study watches for outcomes, such as the development of a disease, during the study period and relates this to other factors such as suspected risk or protection factor(s). (wikipedia.org)
  • The strength of a cohort study is that it is the best way to determine the causes of a disease, condition or issue because it allows researchers to follow one group of people over time and allows researchers to study multiple outcomes at one time. (endvawnow.org)
  • Cloonan YK, Kifle Y, Davis S, Speltz ML, Werler MM, Starr JR. Sleep outcomes in children with hemifacial microsomia and controls: a follow-up study . (bu.edu)
  • Prior to 2005, CDC's method of allocation of TB funds to state and city health departments for prevention and control of TB was based on the burden of TB disease among jurisdictions that had experienced the largest increases in case counts during the TB resurgence that took place from 1985-1993. (cdc.gov)
  • inclusion of sick people is sometimes appropriate, as the control group should represent those at risk of becoming a case. (wikipedia.org)
  • Many valuable case-control studies, such as Lane and Claypon's 1926 investigation of risk factors for breast cancer, were retrospective investigations. (wikipedia.org)
  • A meta-analysis of what were considered 30 high-quality studies concluded that use of a product halved a risk, when in fact the risk was, if anything, increased. (wikipedia.org)
  • In this situation, one may choose to assay all of the cases, and also, for each case, select a certain number of women to assay from the risk set of participants who have not yet failed (i.e. those who have not developed breast cancer before the particular case in question has developed breast cancer). (wikipedia.org)
  • The risk set is often restricted to those participants who are matched to the case on variables such as age, which reduces the variability of effect estimates. (wikipedia.org)
  • CDC provides financial and technical assistance to state, local, and territorial health and educational agencies to implement high-impact programs to prevent and control youth risk behaviors, HIV/AIDS, viral hepatitis, STDs, and tuberculosis (TB). (cdc.gov)
  • Studies of modifiable risk factors for stroke have been conducted largely in developed countries. (diabetesincontrol.com)
  • A case-control study is usually retrospective - the researchers look back at data collected in the past, enabling them to test whether a particular outcome can be linked back to a suspected risk factor. (medicalnewstoday.com)
  • They then compare how often the group of cases had been exposed to the suspected cause (risk factor), versus how often the controls had been exposed. (medicalnewstoday.com)
  • If the risk factor has a greater prevalence among the cases, then this is some evidence to suggest that it is a cause of the disease. (medicalnewstoday.com)
  • Risk factors could be uncovered by researchers studying the medical and lifestyle histories of the people in each group. (medicalnewstoday.com)
  • A prospective case-control study may also be helpful in this scenario as researchers can collect data on suspected risk factors while they monitor for new cases. (medicalnewstoday.com)
  • We explore the benefits and challenges of several options for management of three insect pests in maize crops and an invasive insect pest in forests, including diversifying crop rotations, altering the timing of planting, tillage and irrigation, using less sensitive crops in infested areas, applying biological control agents, and turning to alternative reduced risk insecticides. (springer.com)
  • 1 2 In New Zealand in the 1970s an increase in deaths from asthma corresponded with an increase in prescriptions of the β 2 agonist fenoterol, and several case-control studies 3 and one cohort study 4 found that fenoterol was associated with an increased risk of death from asthma. (bmj.com)
  • The analysis of mobile telephone use and the risk for brain tumor according to anatomic localization was based on these 198 cases with corresponding controls. (medscape.com)
  • Using a tumor induction period of 5 years or more, the risk increased further to an OR of 2.10 (95% CI, 1.25-3.53) based on 36 exposed cases and 37 exposed controls. (medscape.com)
  • In New South Wales, Australia, a case-control study found both parents receiving Tdap ≥4 weeks before disease onset was associated with a significant reduction in risk of early infant pertussis and suggestive of persistent protection in subsequent pregnancies. (aappublications.org)
  • We know of no other studies that have examined a wide range of risk factors for plagiocephaly. (aappublications.org)
  • The aims of this study were to identify and quantify the determinants of NSP, to distinguish those infants most at risk, and to develop strategies that may help prevent NSP while maintaining the integrity of SIDS prevention advice. (aappublications.org)
  • This paper discusses methodological aspects of case-control studies of severe malaria including case and control definitions, selection of cases and controls, potential risk factors, sample size calculations and analysis. (omicsonline.org)
  • This paper showed how to estimate risk and prevalence ratios in case-control studies without a rare-disease requirement by allowing cases into the control group. (epiresearch.org)
  • In 41.1% of the cases, menarche was present under 12 years and in only 14.1% after 14 years, therefore confirming the reduction of mammary cancer risk in women with late menarche. (nih.gov)
  • Case-control studies permit the identification of risk factors for disease and usually requires a much smaller sample size than cohort studies. (endvawnow.org)
  • Based on the conditional logistic linear model, individuals with severe obesity had a higher risk of depression than those in the control group. (scirp.org)
  • Persistent eczema occurred in 174 (0.94%) suicide cases and 285 (0.77%) controls yielding a 22% increased risk of suicide associated with persistent eczema (OR 1.22, 95% CI 1.01 to 1.48, p=0.037). (ices.on.ca)
  • The cases will also be followed to gain information on the natural history of this disease including risk factors for progression of disease. (nih.gov)
  • In this case-control study, we found that several traditional risk factors for DM in the general population were associated with its development in HIV-infected patients. (natap.org)
  • Studies have reported an increased risk of childhood leukaemia associated with living near high-voltage electric power transmission lines that extend to distances at which magnetic fields from lines are negligible. (nature.com)
  • We conducted a large records-based case-control study of childhood leukaemia risk in the population living near power lines in California. (nature.com)
  • The possibility that the electric power transmission and distribution system could pose a risk for childhood cancer has been a concern for several decades, beginning with the study of Wertheimer and Leeper (1979) , which found an association with electrical wiring configurations. (nature.com)
  • One of the key studies to investigate distance from power lines and childhood cancer risk was the study of Draper et al (2005) . (nature.com)
  • If a disease is ridiculously rare, it's virtually impossible to feasibly put together a cohort study comparing relative risk based on the presence/absence of a risk factor because you have no idea who is going to develop that (e.g.) 1/ten million disease. (studentdoctor.net)
  • The inherent structure of the study acknowledges that we couldn't possibly be fully aware of other confounding/risk factors that may have popped up over time. (studentdoctor.net)
  • Danis K , Di Renzi M , O'Neill W , Smyth B , McKeown P , Foley B , Tohani V , Devine M . Risk factors for sporadic Campylobacter infection: an all-Ireland case-control study. (eurosurveillance.org)
  • A population-based case-control study of the rare but devastating neurological disease amyotrophic lateral sclerosis (ALS) has shown that the risk of such disease is increased among smokers, as has been shown previously. (bio-medicine.org)
  • As we have pointed out elsewhere, if helmet use neither increases nor decreases the risk of non-head injuries among cyclists who crash, then the helmet wearing prevalence among controls with non-head injuries should approximate the prevalence of helmet use among all cyclists who crashed and had no head injury. (bmj.com)
  • Operators were challenged with monitoring critical processes, but also had the intensive job of setting up valve transfer paths, dialing-in mixer and pump speeds and adjusting crucial temperature control valves. (rockwellautomation.com)
  • For a producer of tortilla chip snacks the complex interaction between controlling the temperature, cooking time and oil replenishment of its fryers is critical to maintaining the high quality of its tortilla chip snacks. (controlengeurope.com)
  • We found no differences between NMS patients and psychiatric controls in respect of changes in environmental temperature. (wiley.com)
  • Our study supports the need for caution when using intramuscularly administered, abruptly increasing, high-dose neuroleptics, particularly in mentally retarded or agitated patients, regardless of environmental temperature. (wiley.com)
  • These shafts connect to long jack shafts that spread across the roof line of the greenhouse, connecting to multiple rack-and-pinion mechanisms that open and close large glass window panes in the ceiling for temperature control. (theengineer.co.uk)
  • In experimental research, investigators can manipulate one factor while controlling others, and the main research question can be broken down into subquestions with comparatively simple causal assumptions (12). (gfmer.ch)
  • The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. (clinicaltrials.gov)
  • Investigators compared each of the 32 microcephaly cases they found with two controls: the first two infants born the following morning without microcephaly…" (Schnirring, 9/15). (kff.org)
  • For example, if you wanted to test the hypothesis that a disease seen in adulthood is linked to factors occurring in young childhood, a prospective study would take decades to do. (medicalnewstoday.com)
  • Cases were children aged ≤5 years with radiological CAP.The aim of the study was to assess the association between specific respiratory viruses and childhood CAP. (google.com)
  • The study indicates viral CAP is an underestimated disease and points out hMPV as a new important target for the prevention of childhood CAP. (google.com)
  • BACKGROUND The relation of parental smoking to wheezing and asthma occurring after the first year of life was assessed by a systematic quantitative review of case-control and longitudinal studies, complementing earlier reviews of cross sectional surveys and wheezing in early childhood. (bmj.com)
  • Childhood cognitive deterioration in 22q11.2DS has previously been reported, but only in studies lacking a control sample. (cambridge.org)
  • The study included 5788 childhood leukaemia and 3308 central nervous system (CNS) cancer cases (for comparison) born in and diagnosed in California (1986-2008), and matched to population-based controls by age and sex. (nature.com)
  • These authors reported a case-control study of childhood cancer in relation to the distance from birth address to the nearest high-voltage overhead transmission line (mostly of 275 or 400 kv) among children born in England and Wales in 1962-1995. (nature.com)
  • Violence Policy Center analysts looked at all federal firearms cases tied to Mexican gun traffickers they could find in California and three other states from 2006 to 2009. (kpbs.org)
  • Children ≤18 years old within 2 years of MS onset or controls without autoimmune disorders attending a University of California, San Francisco, USA, pediatric clinic were examined for fecal bacterial community composition and predicted function by 16S ribosomal RNA sequencing and phylogenetic reconstruction of unobserved states (PICRUSt) analysis. (nih.gov)
  • We demonstrate that, following Proposition 99, tobacco consumption fell markedly in California relative to a comparable synthetic control region. (psu.edu)
  • In 1989, California became "the first state to ban assault weapons," and since that time, it has enacted a steady stream of gun controls, only to see violent crime rise and high-profile shootings-including terror attacks-betray the lie that gun control saves lives. (gunowners.org)
  • Think about it like this: before the new gun controls were even signed on July 1, California had universal background checks, which means no "gun show loophole," a ten-day waiting period on gun purchases, firearm registration requirements, Gun Violence Restraining Orders, other means of firearm confiscation, and requirements for concealed carry permit holders that are so stringent getting a concealed carry permit in California is a herculean task. (gunowners.org)
  • 4 Researchers could also restrict the study base to population segments with anticipated higher response proportions such as people with identifiable telephone numbers. (lww.com)
  • Case-control research is a central tool used by epidemiologists, researchers who look into the factors that affect the health and illness of populations. (medicalnewstoday.com)
  • There are multiple reasons why case-control studies are useful to researchers. (medicalnewstoday.com)
  • By the end of the lectures you should be able to identify which study types are being used and why the researchers selected them when you are reading a paper. (coursera.org)
  • Brazilian researchers [Thursday] added an eagerly awaited piece of the Zika-microcephaly puzzle, publishing the first case-control study , which found a strong link between the two conditions. (kff.org)
  • The study is the first time researchers have used social contact data to quantify the potential impact of control measures on reducing individual-level transmission of SARS-CoV-2 in specific settings. (cam.ac.uk)
  • In the study, researchers analysed data on how 40,162 people moved about the UK and interacted with others prior to COVID-19 to simulate how combinations of different testing, isolation, tracing, and physical distancing scenarios-such as app-based tracing, remote working, limits on different sized gatherings, and mass population-based testing-might contribute to reducing secondary cases . (cam.ac.uk)
  • The researchers calculated that, had no control measures been implemented, R would be 2.6-meaning that one infected person would infect, on average, 2-3 more people. (cam.ac.uk)
  • In several situations they have greater statistical power than cohort studies, which must often wait for a 'sufficient' number of disease events to accrue. (wikipedia.org)
  • Cincinnati, OH: U.S. Department of Health Education and Welfare, Public Health Service, Center for Disease Control, National Institute for Occupational Safety and Health, DHEW (NIOSH) Publication No. 79-117. (cdc.gov)
  • A study of benign prostatic hypertrophy might be misleading if cases were identified from hospital admissions and admission to hospital was influenced not only by the presence and severity of disease but also by other variables, such as social class. (bmj.com)
  • The cohort study starts with the putative cause of disease, and observes the occurrence of disease relative to the hypothesized causal agent, while the case-control study proceeds from documented disease and investigates possible causes of the disease. (gfmer.ch)
  • Depending on the time when the cohort study is initiated relative to occurrence of the disease(s) to be studied, one distinguishes between current and historical cohort studies. (gfmer.ch)
  • Eight cases and 11 controls reported previous radiotherapy for benign or malignant disease, yielding an OR of 1.58 (95% CI, 0.60-4.16). (medscape.com)
  • Case-control studies in which children with severe disease are compared with children with non-severe disease and with community controls, avoid some of the ethical and logistical problems inherent in such an undertaking. (omicsonline.org)
  • Cases and controls generally are matched according to specific characteristics (eg, age, sex, or duration of disease) to reduce by these variables. (amamanualofstyle.com)
  • Nigeria and Senegal, two of the five countries affected by the world's worst ever Ebola outbreak are managing to halt the spread of the disease, the World Health Organization said on Monday, although the overall death toll rose to 2,793 out of 5,762 cases. (ibtimes.co.uk)
  • Introduction For simplicity we first consider measurement of the relationship between a disease (0) and an agent under study (E) in the presence of a single confounding variable Z. Extensions to the more realistic case where a set of variables are candidates for adjustment are outlined in Section 2.4. (epa.gov)
  • Both TLR8 and TLR7 are functional candidate genes owing to their key roles as pathogen recognition receptors and, in the case of TLR7 , overexpression has been associated directly with murine autoimmune disease. (nature.com)
  • Forum reviewers thought that this was a well-done and important paper, as it is a population-based analysis, with almost 500 cases of ALS, a very large number of cases for this rare disease. (bio-medicine.org)
  • One of the most significant triumphs of the case-control study was the demonstration of the link between tobacco smoking and lung cancer, by Richard Doll and Bradford Hill. (wikipedia.org)
  • Several studies have used standard cohort analyses to study precursors to breast cancer, e.g. use of hormonal contraceptives, which is a covariate easily measured on all of the women in the cohort. (wikipedia.org)
  • Cancer Causes Control. (wikipedia.org)
  • Controls were comprised of individuals with no history of skin cancer who screened negative for skin cancer upon physical examination at the affiliated cancer screening or primary care clinics ( n = 315). (springer.com)
  • Perea-Milla LE, Minarro-Del Moral RM, Martinez-Garcia C, Zanetti R, Rosso S, Serrano S, Aneiros JF, Jimenez-Puente A, Redondo M (2003) Lifestyles, environmental and phenotypic factors associated with lip cancer: a case-control study in southern Spain. (springer.com)
  • In our retrospective study 146 women suffering from breast cancer, treated in our Institute from 1970 to 1993, were enrolled. (nih.gov)
  • Dietary pattern analysis is a powerful technique to study the relationships between diet and cancer, accounting for the specificities of overall dietary intake in each setting. (unboundmedicine.com)
  • Smoking restrictions are an important component of tobacco control policy because they protect non-smokers from the adverse health effects of passive smoking 1-5 and facilitate smokers' decisions to quit or cut down. (bmj.com)
  • By utilizing data previously collected from a large cohort study, the time and cost of beginning a new case-control study is avoided. (wikipedia.org)
  • Individuals exposed to the agent under study (index subjects) are followed over time and their health status is observed and recorded during the course of the study. (gfmer.ch)
  • Though weight data was already being collected in the carbon molding area, we needed to implement a paperless system to help the operators respond in real-time to out-of-control signals," says Ben Fisher, product manufacturing engineer at Trek. (qualitymag.com)
  • Calculating control limits and periodically checking the process capability were time consuming and tedious. (qualitymag.com)
  • Using InfinityQS (Chantilly, VA) software for real-time statistical process control (SPC), Trek was able to automate its quality control procedures. (qualitymag.com)
  • In this paper, we consider optimal control problems with multiple time delays in state and control variables and present two applications in biomedicine. (aimsciences.org)
  • L. Göllmann and H. Maurer , Theory and applications of optimal control problems with multiple time-delays, Journal of Industrial and Management Optimization , 10 (2014), 413-441. (aimsciences.org)
  • As such, it needed to maximise operator efficiency, provide complete accountability in case of incidents and deliver clear return on investment over time. (bsia.co.uk)
  • all exposed cases were currently on IMD treatment at the time of the stool sample, the naïve cases had never been exposed to an IMD. (nih.gov)
  • You have the right to withdraw or change your consent at any time by contacting Trend Control Systems. (buildingdesign.co.uk)
  • Given the inherent time frame required of this approach, it can be very challenging to employ such a study in conflict and post-conflict settings where conditions can change rapidly. (endvawnow.org)
  • Case-control studies are relatively simple and economical to carry out, but the one weakness is that only one outcome may be studied at a time. (endvawnow.org)
  • The controls were matched with the subjects according to place of residence, age, time that pension was granted, and occupation. (scirp.org)
  • Another important number is what's called doubling time - how long it takes the number of cases to double. (ibtimes.co.uk)
  • Cases included those conducted with first-time AMI or any AMI cases. (bmj.com)
  • When individual trajectories were examined, some participants showed significant decline over time, but the prevalence was similar for 22q11.2DS and control siblings. (cambridge.org)
  • So case-control studies are good for rare diseases because they're most practical ( because they save a ton of money and time). (studentdoctor.net)
  • And looking back in time (a retrospective study) costs less because following people forward in time understandably, in and of itself, would have to require money and time. (studentdoctor.net)
  • But any time you pick and choose who is in your study, there exists the chance you're inadvertently picking and choosing people who share a second variable. (studentdoctor.net)
  • Since you're looking back in time with a case-control study, not only are we non-random, but we also know people are poor historians. (studentdoctor.net)
  • However, the authors note that the model is based on a series of assumptions about the effectiveness of testing, tracing, isolation, and quarantine-for example about the amount of time it takes to isolate cases with symptoms (average 2.6 days) and the likelihood that their contacts adhere to quarantine (90%)-which, although plausible, are optimistic. (cam.ac.uk)
  • This case study presents how electronics and software can be applied to a mobile hydraulic application, as well as how electro-hydraulics have evolved over time. (powertransmission.com)
  • The case histories were chosen primarily because the amount of noise reduction actually achieved was measured. (cdc.gov)
  • Parental reduced antigen diphtheria-tetanus-acellular pertussis (Tdap) vaccination is difficult to implement, and empirical data on its impact is limited to a single hospital-based study in Texas, which found no reduction in infant pertussis hospitalization. (aappublications.org)
  • T. Guinn , Reduction of delayed optimal control problems to nondelayed problems, Journal of Optimization Theory and Applications , 18 (1976), 371-377. (aimsciences.org)
  • If you are using more than one control per case then this function also provides the reduction in sample size relative to a paired study that you can obtain using your number of controls per case ( Dupont, 1988 ). (statsdirect.com)
  • Achieving such a thorough level of contact tracing may be impractical, but the new study suggests that a large reduction in transmission could also be achieved by supplementing with moderate physical distancing measures. (cam.ac.uk)
  • R. F. Hartl , S. P. Sethi and R. G. Vickson , A survey of the maximum principles for optimal control problems with state constraints, SIAM Review , 37 (1995), 181-218. (aimsciences.org)