Figure 2.

Obtaining summary (overall) metrics for medical test performance. PLR/NLR = positive (negative) likelihood ratio; PPV/NPV = positive (negative) predictive value; Prev = prevalence; Se = Sensitivity; Sp = specificity. The herein recommended approach is to perform a meta-analysis for sensitivity and specificity across the K studies, and then use the summary sensitivity and specificity (Se₊ and Sp₊; a row of two boxes after the horizontal black line) to back-calculate “overall” values for the other metrics (second row of boxes after the horizontal black line). In most cases it is not meaningful to synthesize prevalences (see text).