FIG 4.

Summary receiver operating characteristic (SROC) plot for NAA tests against culture. The SROC plot shows a summary of test performance, visual assessment of the threshold effect, and the heterogeneity of the data in ROC space between sensitivity (SENS) and specificity (SPEC); each circle in the SROC plot represents a single study, and the summary operating sensitivity, specificity, and SROC curve with both confidence and prediction regions are shown. The dashed line that is around the pooled point estimate shows the 95% confidence region. The area under the curve (AUC) acts as an overall measure of test performance. In particular, when AUC is between 0.8 and 1, the accuracy is relatively high. If the SROC curve were in the upper left corner, it would show the best combination of sensitivity and specificity for the diagnostic test. The number of studies which used NAA tests against culture is shown within each circle.