Your screening test for yellow fever had a sensitivity of 88%, a specificity of 74% and a positive predictive value of 82% last year. This year there is an outbreak of yellow fever in the region increasing prevalence rates. You would expect the positive predictive value of the screen to:
A) Be higher than 82% this year
B) To remain at about 82% this year
C) To be below 82% this year
D) Unable to determine without the prevalence rate

Question

Quizplus · Accepted Answer

The positive predictive value (PPV) increases with an increase in disease prevalence. Since there is an outbreak, the prevalence of yellow fever has increased, leading to a higher PPV than 82%.

Your Screening Test for Yellow Fever Had a Sensitivity of 88