NR 503 (Epidemiology)-Week 3.docx

Absolute Risk - correct answer The incidence of disease in a population Attributable Risk - correct answer How much of the risk (incidence) of the disease we hope to prevent if able to eliminate exposure to the agent in question clinical significance - correct answer referring to results that have clinical significance External validity (generalizability) - correct answer The generalizability of the results to other populations False Negative - correct answer Occurs when the test incorrectly reports the absence of disease when disease is, in fact, present False Positive Test - correct answer Occurs when the test incorrectly reports disease presence when disease is, in fact, absent Gold standard - correct answer Tests with 100% sensitivity and specificity Hierarchy of Research - correct answer editorials, expert opinion case series, case reports case-control studies cohort studies randomization controlled trials systematic reviews Incidence Rate - correct answer The number of new cases of a disease that occurs during a specified period of time in a population at risk for developing the disease internal validity - correct answer Whether the study measures what it is suppose to measure Likelihood ratio - correct answer combines sensitivity and specificity data to help the clinician quantify how much the odds of disease change based on a positive or a negative test result natural history of disease - correct answer Nature of the disease and how it progresses Necessary and Sufficient Causal relationship - correct answer A factor in both necessary (disease will occur only if the factor is present) AND sufficient (exposure always leads to disease). Rarely encountered. Example: infectious diseases. 100 people may be exposed to an infectious disease, but not everyone develops the disease because there are other variables involved (immune status, low infectivity rate) Necessary BUT not sufficient - correct answer More than one factor is required, usually in a temporary sequence. The initiation and promotion stages associated with carcinogenesis models examples of this type of casual relation. Example: when considering tuberculosis, the tubercle bacillus is a necessary factor, but even its presence may not be sufficient to produce the disease in every individual. Negative Predictive Value (NPV) - correct answer The probability of the person being free of disease The disease when the screening test or diagnostic test is negative Neither sufficient NOR necessary - correct answer A specific factor can be combined with other factors to produce disease. However, the disease may be produced even in the absence of the factor. Occurs in chronic disease Example: multiple risk factors for the development of heart disease are neither sufficient nor necessary.