True or false n A diagnostic test with a negative predictive value of 0 75 means that of those patients testing negative, 75 actually have the disease T F o A diagnostic test with a sensitivity of 0 5 and a specificity of 0 5 means that a patient receiving such a test has a 50 probability of truly having the disease if testing positive and a 50 probability of not having the disease if testing negative T F p Assuming equivalent test validity and reliability across communities, screening tests conducted in communities with a high prevalence of the disease being screened for will have higher yields than if done in communities with lower prevalence of the disease T F q A screening test with 99 specificity and 99 sensitivity will necessarily have higher predictive values than a screening test with 50 specificity and 50 sensitivity T F r Positive predictive value of a screening test depends on its sensitivity and specificity and the prevalence of the disease being tested for in the community T F s Negative predictive value of a screening test depends on its sensitivity and specificity and the prevalence of the disease being tested for in the community T F t If it's worse to have false positives than false negatives, the specificity of the screening test should be maximized T F u If it's found that participants in a screening program were much less likely to die from the disease screened for after 20 years of follow up compared to non participants, then the screening program must have been the reason for the reduced mortality T F v Prevalence is a measure of association used to estimate the rate of disease occurrence in studies of screening programs T F w Incidence is a measure of disease frequency used to estimate the risk or rate of exposure in diagnostic test studies T F x A number needed to screen of 20,000 would mean that for every 100,000 people screened, 5 would benefit T F y A screening program with a number needed to harm of 1000 would be consistent with a risk of harm of 0 002 in the screening group and 0 001 in those not screened T F

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Question: True or false n. A diagnostic test with a negative predictive value of 0.75 means that of those patients testing negative, 75% actually have the

True or false

n. A diagnostic test with a negative predictive value of 0.75 means that of those patients testing negative, 75% actually have the disease.	T	F
o. A diagnostic test with a sensitivity of 0.5 and a specificity of 0.5 means that a patient receiving such a test has a 50% probability of truly having the disease if testing positive and a 50% probability of not having the disease if testing negative.	T	F
p. Assuming equivalent test validity and reliability across communities, screening tests conducted in communities with a high prevalence of the disease being screened for will have higher yields than if done in communities with lower prevalence of the disease.	T	F
q. A screening test with 99% specificity and 99% sensitivity will necessarily have higher predictive values than a screening test with 50% specificity and 50% sensitivity.	T	F
r. Positive predictive value of a screening test depends on its sensitivity and specificity and the prevalence of the disease being tested for in the community.	T	F
s. Negative predictive value of a screening test depends on its sensitivity and specificity and the prevalence of the disease being tested for in the community.	T	F
t. If it's worse to have false positives than false negatives, the specificity of the screening test should be maximized.	T	F
u. If it's found that participants in a screening program were much less likely to die from the disease screened for after 20 years of follow-up compared to non-participants, then the screening program must have been the reason for the reduced mortality.	T	F
v. Prevalence is a measure of association used to estimate the rate of disease occurrence in studies of screening programs.	T	F
w. Incidence is a measure of disease frequency used to estimate the risk or rate of exposure in diagnostic test studies.	T	F
x. A number needed to screen of 20,000 would mean that for every 100,000 people screened, 5 would benefit.	T	F
y. A screening program with a number needed to harm of 1000 would be consistent with a risk of harm of 0.002 in the screening group and 0.001 in those not screened.	T	F