Test characteristics of mortality prediction rules for HIV-associated PCP
| Rule | Number of risk factors (n = 363) | Sensitivity (%) | Specificity (%) | PPV (%) | NPV (%) |
| Five predictors* | >0 | 100 | 0 | 12.1 | NA |
| >1 | 100 | 12.5 | 13.6 | 100 | |
| >2 | 88.6 | 41.1 | 17.2 | 96.3 | |
| >3 | 63.6 | 75.2 | 26.2 | 93.8 | |
| >4 | 34.1 | 95.0 | 48.4 | 91.3 | |
| >5 | 11.4 | 100 | 100 | 89.1 | |
| Three predictors† | >0 | 100.0 | 0.0 | 12.1 | NA |
| >1 | 100.0 | 19.7 | 14.7 | 100 | |
| >2 | 63.6 | 62.4 | 18.9 | 92.6 | |
| >3 | 40.9 | 93.4 | 46.2 | 92.0 |
*Predictors are age, alveolar–arterial oxygen gradient (A–a O2 gradient), albumin, total bilirubin and recent injection drug use.
†Predictors are age, A–a O2 gradient and albumin.
NPV, negative predictive value; PCP, Pneumocystis pneumonia; PPV, positive predictive value.