Predictors of in-hospital vs postdischarge mortality in pneumonia

Many patients who die within 30 days of admission to the hospital for pneumonia die after discharge. Recently, 30-day mortality for patients with pneumonia became a publicly reported performance measure, meaning that hospitals are, in part, being measured based on how the patient fares after discharge from the hospital. This study was undertaken to determine which factors predict in-hospital vs postdischarge mortality in patients with pneumonia.

This was a retrospective analysis of a database of 21,223 patients on Medicare aged 65 years and older admitted to the hospital between 2000 and 2001. Multivariate logistic regression analyses were performed to determine the association between 26 patient characteristics and the timing of death (in-hospital vs postdischarge) among those patients who died within 30 days of hospital admission.

Among the 21,223 patients, 2,561 (12.1%) died within 30 days of admission: 1,343 (52.4%) during the hospital stay, and 1,218 (47.6%) after discharge. Multivariate logistic regression demonstrated that seven factors were significantly associated with death prior to discharge: systolic BP < 90 mm Hg, respiration rate > 30/min, bacteremia, arterial pH < 7.35, BUN level > 11 mmol/L, arterial Po(2) < 60 mm Hg or arterial oxygen saturation < 90%, and need for mechanical ventilation. Some underlying comorbidities were associated with a nonstatistically significant trend toward death after discharge.

Of elderly patients dying within 30 days of admission to the hospital, approximately one-half die after discharge from the hospital. Comorbidities, in general, were equally associated with death in the hospital and death after discharge