Skip to main content
. Author manuscript; available in PMC: 2009 Dec 1.
Published in final edited form as: Fertil Steril. 2008 Apr 22;90(6):2196–2202. doi: 10.1016/j.fertnstert.2007.10.080

Table 2.

Changes in the predictive ability of screening tests based on changes in prevalence of disease

Age Pretest probability Pre-test odds Post-test Odds Positive predictive value Negative predictive value
Probability of a test with 95% sensitivity and specificity 30 0.02 (2/100) 0.02 0.39 0.27 0.99
38 0.10 (10/100) 0.11 2.09 0.68 0.99
40 0.30 (30/100) 0.43 8.14 0.89 0.98
Probability of a test with 98% sensitivity and 60% specificity 30 0.02 (2/100) 0.02 0.05 0.05 0.99
38 0.10 (10/100) 0.11 0.27 0.21 0.99
40 0.30 (30/100) 0.43 1.05 0.51 0.99
Probability of a test with 71% sensitivity and 98% specificity* 30 0.02 (2/100) 0.02 0.72 0.42 0.99
38 0.10 (10/100) 0.11 3.6 0.80 0.97
40 0.30 (30/100) 0.43 15.2 0.94 0.89
*

Best combination test using mean day 3 FSH + mean day 10 inhibin B over 2 cycles.

A combination test of AFC, inhibin B, and basal FSH yields a 75% sensitivity and a 95% specificity, thus yield post-test probability of 23%, 60%, 82% for 30, 38, and 40 year-old women consecutively.