Table 2.

Meta-Regression-Based Comparison of Diagnostic Performance

Meta-analysis metric	≤3 hours	>3 hours	p-Value for the comparison across subgroups
Summary sensitivity (percent)	80 (64 to 90)	96 (85 to 99)	0.036
Summary specificity (percent)	97 (94 to 98)	97 (95 to 99)	0.56

Results based on a bivariate meta-regression that effectively compared the summary sensitivity and summary specificity according to the timing of the last serial CK-MB measurement for diagnosis of acute cardiac ischemia. The meta-regression is on a variable that takes the value 1 if the time from the onset of symptoms to testing was 3 hours or less, and the value 0, when the respective time interval was more than 3 hours. The bivariate meta-regression model allows for different effects of timing on sensitivity and specificity. To facilitate interpretation, we present the summary sensitivity and specificity in each subgroup, calculated from the parameters of the meta-regression model, which also gave the p-values for the effect of timing on test performance.