Dysrhythmia hazard after hospitalization for myocardial infarction: prognosis by ejection fraction compared with signal-averaged ECG

The authors retrieved reports of left ventricular ejection fraction (LVEF) and signal-averaged ECGs (SAECG) used to predict risk of a dysrhythmic event. From each report the number of cases with and without events was extracted to establish accurate values for true positive rate (tpr=sensitivity) and false positive rate (fpr=1 minus specificity). For all the LVEF reports these values were collected and tpr values were plotted vs fpr. The (fpr,tpr) data were summarized by a meta ROC graph using the method of Moses and Shapiro (1993). A composite weighted mean value and 95% confidence interval were also derived. A summary meta-ROC curve for the SAECG reports was similarly obtained. Meta-ROC analysis of multiple reports better summarizes the performances of different prognostic methods, and allows the effect of combining tests for a larger population to be simulated