Figure 2.

SROC curves from the bivariate model for (a) proven+probable vs. no IA, (b) proven+probable vs. possible+no IA, (c) proven+probable+possible vs. no IA, and (d) other, respectively. The smaller region (confidence contour) contains likely combinations of the mean value of sensitivity and specificity. The wider region (prediction contour) demonstrates more uncertainty as to where the likely values of sensitivity and specificity might occur for individual studies. SROC = summary receiver operating characteristic.