Background: Pneumocystis carinii is the leading opportunistic pulmonary infection in HIV-infected patients. Invasive diagnostic procedures might be avoided if available electronic data can accurately identify patients with Pneumocystis pneumonia (PCP).
Methods: We extracted data from electronic hospital records, emergency department records, and a pathology database for 299 HIV-infected patients with pneumonia who underwent bronchoscopy. We identified independent indicators of confirmed PCP using logistic regression analysis on a random half of the patients and validated the predictive power of the resulting model on the other half.
Results: Bronchoscopy confirmed pneumocystis carinii in 111 patients (37%). Five of the seven significant independent predictors of PCP came from patients' electronic medical records: infiltrate on chest radiograph, male gender, lower red cell distribution width, lower serum creatinine, and a prior positive HIV test. The other two (duration of illness and presence of dyspnea) came from the emergency department record. A simple index found 43% of patients at low risk (18% with pneumocystis), 37% at moderate risk (36% with pneumocystis), and 20% at high risk (74% with pneumocystis).
Conclusions: Data from electronic medical records can help quantify the risk of PCP among HIV-infected patients. However, the model failed to identify 18% of patients with PCP in the low risk group, and empiric therapy would erroneously treat 26% of patients classified as high risk. Bronchoscopy is needed to accurately diagnose PCP among HIV-infected patients with pneumonia. However, if bronchoscopy is not available, the model can help with initial decisions about antibiotic therapy.