A new preadmission staging system for predicting inpatient mortality from HIV-associated Pneumocystis carinii pneumonia in the early highly active antiretroviral therapy (HAART) era

A common severe complication of human immunodeficiency virus (HIV) infectio n has been Pneumocystis carinii pneumonia (PCP). Recently, with increasing use of PCP prophylaxis and multidrug antiretroviral therapy, the clinical m anifestations of HIV infection have changed dramatically and the predictors of inpatient mortality for PCP may have also changed. We developed a new s taging system for predicting inpatient mortality for patients with HIV-asso ciated PCP admitted between 1995 and 1997. Trained abstractors per formed c hart reviews of 1,660 patients hospitalized with HIV-associated PCP between 1995 and 1997 at 78 hospitals in seven metropolitan areas in the United St ates. The overall inpatient mortality rate was 11.3%. Hierarchically optima l classification tree analysis identified an ordered five-category staging system based on three predictors: wasting, alveolar-arterial oxygen gradien t (AaPo(2)), and serum albumin level. The mortality rate increased with sta ge: 3.7% for Stage 1, 8.5% for Stage 2, 16.1% for Stage 3, 23.3% for Stage 4, and 49.1% for Stage 5. This new staging system may be useful for severit y of illness adjustment in the current era while exploring current variatio n in HIV-associated PCP inpatient mortality rates among hospitals and acros s cities.