Background: Although the use of antiretroviral therapy has led to dramatic declines in AIDS-associated mortality, Pneumocystis pneumonia (PCP) remains a leading cause of death in HIV-infected patients.
Objectives: To measure mortality, identify predictors of mortality at time of illness presentation, and derive a PCP mortality prediction rule that stratifies patients by risk for mortality.
Methods: Observational cohort study with case note review of all HIV-infected persons with a laboratory diagnosis of PCP at San Francisco General Hospital from 1997-2006.
Results: 451 patients were diagnosed with PCP on 524 occasions. In-hospital mortality was 10.3%. Multivariate analysis identified five significant predictors of mortality: age (adjusted odds ratio [AOR] per 10-year increase, 1.69; 95% confidence interval [CI] 1.08-2.65; p=0.02); recent injection drug use (AOR 2.86; 95% CI 1.28-6.42; p=0.01); total bilirubin >0.6 mg/dL (AOR 2.59; 95% CI 1.19-5.62; p=0.02); serum albumin <3 g/dL (AOR 3.63; 95% CI 1.72-7.66; p=0.001); and alveolar-arterial oxygen gradient ≥50 mm Hg (AOR 3.02; 95% CI 1.41-6.47; p=0.004). Using these five predictors, we derived a six point PCP mortality prediction rule that stratifies patients according to increasing risk of mortality: score 0-1, 4%; score 2-3, 12%; score 4-5, 48%.
Conclusions: Our PCP mortality prediction rule stratifies patients by mortality risk at the time of illness presentation and should be validated as a clinical tool.