Epidemiology Final Exam| 55 questions| with complete solutions

Double-Blind Design correct answer: Feature of a clinical trial in which neither the subject nor the experimenter is aware of the subject's group assignment in relation to control or treatment status. Outbreak Investigation Steps correct answer: 1. Identify investigation team and resources 2. Establish existence of an outbreak 3. Verify diagnosis 4. Construct case definition 5. Find cases systematically and list 6. Develop hypotheses 7. Test hypotheses 8. Perform additional studies as necessary 9. Implement control measures 10. Communicate findings 11. Maintain surveillance Factors that have contributed to the decrease in children with elevated blood levels correct answer: Reduced lead in paint and gasoline Sensitivity correct answer: Ability of a test to identify correctly all screened individuals who actually have the disease being screened for. Formula: (a/a+c) (TP/TP+FN) X 100 % Specificity correct answer: Ability of a test to identify non-diseased individuals who actually do NOT have the disease. Formula: (d/b+d) TN/TN+FP X 100 % Healthy Worker Bias (Effect) correct answer: Error linked to the observation that employed persons tend to have lower mortality rates than the general population; stems from the fact that good health is necessary for obtaining and maintaining employment. refers to fact that very ill & disabled, older people, are typically excluded from working populations, & so on average workers appear to be healthier than general population Odds Ratio (OR) correct answer: CASE-CONTROL: Measure of association between frequency of exposure and frequency of outcome used in case-control studies. Formula: (AD)/(BC) OR 1: implies no association OR >1: Cases likely to be exposed OR <1: Exposure as a protective factor Risk Ratio (Relative Risk) (RR) correct answer: COHORT: Provides a direct measure of association between exposure and outcome Formula: Incidence rate in exposed / incidence ra