Table 2.
2 × 2 contingency tables and performance characteristics of four algorithms (excluding outside cases) for the identification of incident syphilis among HIV-positive men who have sex with men, Boston, MA, 2016–2017.
| Algorithm A | Algorithm B | ||||||
|---|---|---|---|---|---|---|---|
| Chart review |
Chart review |
||||||
| Algorithm | Positive | Negative | Total | Algorithm | Positive | Negative | Total |
| Positive | 136 | 5 | 141 | Positive | 143 | 6 | 149 |
| Negative | 44 | 1526 | 1570 | Negative | 37 | 1525 | 1562 |
| Total | 180 | 1531 | 1711 | Total | 180 | 1531 | 1711 |
| Sens, % | Spec, % | PPV, % | NPV, % | Sens, % | Spec, % | PPV, % | NPV, % |
| 75.6 | 99.7 | 96.4 | 97.2 | 79.4 | 99.6 | 96.0 | 97.6 |
| Algorithm C | Algorithm D | ||||||
| Chart review |
Chart review |
||||||
| Algorithm | Positive | Negative | Total | Algorithm | Positive | Negative | Total |
| Positive | 166 | 4 | 170 | Positive | 169 | 5 | 174 |
| Negative | 14 | 1520 | 1534 | Negative | 11 | 1518 | 1529 |
| Total | 180 | 1524 | 1704 | Total | 180 | 1523 | 1703 |
| Sens, % | Spec, % | PPV, % | NPV, % | Sens, % | Spec, % | PPV, % | NPV, % |
| 92.2 | 99.7 | 97.6 | 99.1 | 93.9 | 99.7 | 97.1 | 99.2 |
NPV, negative predictive value; PPV, positive predictive value; RPR, rapid plama reagin; sens, sensitivity; spec, specificity