Paired comparison of the sensitivity and specificity of the MACS and T-MACS models for ACS in the derivation and validation studies
| MACS | T-MACS | Absolute difference (95% CI), p value* | |
|---|---|---|---|
| Derivation set | |||
| Sensitivity | 99.3 (96.4–100.0) | 98.7 (95.3–99.8) | 0.7% (−0.6 to 0.7), p=1.00 |
| Specificity | 45.2 (40.9–49.4) | 47.6 (43.4–51.9) | 2.8% (1.0 to 3.8), p=0.003 |
| Validation set | |||
| Sensitivity | 100.0% (95% CI 98.1% to 100.0%) | 98.4% (95.4%–99.7%) | 1.6% (95% CI−0.7% to 1.6%), p=0.25 |
| Specificity | 20.9% (95% CI 18.6% to 22.4%) | 46.8% (43.9%–49.8%) | 25.9% (95% CI 25.3% to 25.9%), p<0.0001 |
*McNemar's test for paired proportions. N=698 in the derivation set and N=1331 in the validation set (5 patients in the derivation set and 131 in the validation set did not have an available sample for measurement of heart-type fatty acid binding protein concentration and were therefore not included in this analysis). This explains the minor differences in sensitivity and specificity compared with those reported in table 3.
ACS, acute coronary syndromes; T-MACS, Troponin-only Manchester Acute Coronary Syndromes.