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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
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A test has high false positive rate in a community. True is
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The correct answer is  Ans is 'd' i.e. Low prevalence "In a population with a low prevalence of a particular disease, it is likely that most of the positive results in a screening program for that disease would be falsely positive."- Epidemiology, biostatistics, and preventive medicine By James F. Jekel, David L. Katz, Joann G. Elmore 2/e p120"In a high-prevalence population, the absolute number of false-positives is small in comparison with the absolute numbers of true positives. In a low-prevalence population, the absolute number of false-positives is large in comparison with the absolute number of true positives." -The basic science of oncology By Ian Tannock 4/e p486, 487The no. of false positive varies inversely with the prevalence of disease in population. This means that when the same test is applied to two populations with differing prevalence; false positive cases would be more in the population with low prevalence and false positive cases would be low in the population with high prevalence.Also Note:Sensitivity and specificity are characteristic of a particular test and do not depend on the prevalence of disease in the population being tested.The positive predictive value and the negative predictive value depend on characteristics of both the test (sensitivity and specificity) and the population being tested (prevalence of disease). The positive predictive value is directly proportional to the prevalence. The negative predictive value is inversely proportional to prevalence.As the prevalence of disease declines, the positive predictive value of the test declines and the negative predictive value increases.