CLINICAL PREDICTORS OF PNEUMOCYSTIS-CARINII PNEUMONIA, BACTERIAL PNEUMONIA AND TUBERCULOSIS IN HIV-INFECTED PATIENTS

Background: Clinicians are frequently faced with the differential diag nosis between Pneumocystis carinii pneumonia (PCP), bacterial pneumoni a, and pulmonary tuberculosis in HIV-infected patients. Objectives: To identify features that could help differentiate these three pneumonia types at presentation by evaluating the clinical characteristics of t he three diagnoses among patients at two urban teaching hospitals. Des ign: Retrospective chart review. Methods: Cases were HIV-infected pati ents with a verified hospital discharge diagnosis of PCP (n = 99), bac terial pneumonia (n = 94), or tuberculosis (n = 36). Admitting notes w ere reviewed in a standardized manner; univariate and multivariate ana lyses were used to determine clinical predictors of each diagnosis. Re sults: Combinations of variables with the highest sensitivity, specifi city, and odds ratios (OR) were as follows: for PCP, exertional dyspne a plus interstitial infiltrate (sensitivity 58%, specificity 92%; OR, 16.3); for bacterial pneumonia, lobar infiltrate plus fever less than or equal to 7 days duration (sensitivity 48%, specificity 94%; OR, 14. 6); and for tuberculosis, cough > 7 days plus night sweats (sensitivit y 33%, specificity 86%; OR, 3.1). On regression analysis, independent predictors included interstitial infiltrate (OR, 10.2), exertional dys pnea (OR, 4.9), and oral thrush (OR, 2.9) for PCP; rhonchi on examinat ion (OR, 12.4), a chart mention of `toxic' appearance (OR, 9.1), fever less than or equal to 7 days (OR, 6.6), and lobar infiltrate (OR, 5.8 ) for bacterial pneumonia; and cavitary infiltrate (OR, 21.1), fever > 7 days (OR, 3.9), and weight loss (OR, 3.6) for tuberculosis. Conclus ions: Simple clinical variables, all readily available at the time of hospital admission, can help to differentiate these common pneumonia s yndromes in HIV-infected patients. These findings can help to inform c linical decision-making regarding choice of therapy, use of invasive d iagnostic procedures, and need for respiratory isolation. (C) 1998 Lip pincott-Raven Publishers.