This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Social & Preventive Medicine
More false positive cases in a community signify that the disease has: 
Select and explain. 
A. High prevalence, B. High sensitivity, C. Low prevalence, D. Low sensitivity
C: Low prevalence
Answer: C: Low prevalence 
Explanation: There will be more false positive cases in a community where prevalence is low, because the predictive accuracy of the test is decreased. This predictive value however depends on the prevalence of a disease (besides its sensitivity and specificity). The more prevalent a disease in a given population, the more is the predictive value of a given test. Thus, the more prevalent a disease, the more will be the True positive and the less will be the false positive. The less prevalent a disease, the less will be the True positive and the more will be the false positive. Thus there will be more false positive cases in a community where prevalence is less because, the predictive accuracy of the test is decreased. Low prevalence is the best answer. More prevalent disease Less false positive results Less prevalent disease More false positve results Ref:Park's Textbook of Preventive and Social Medicine By K. Park, 19th Edition, Page 119