Study objective: To determine the incidence, causes, and outcomes of patients hospitalized within 30 days of initiating outpatient treatment for community-acquired pneumonia (CAP).
Design: Patients were enrolled in the Pneumonia Patient Outcomes Research Team's multicenter, prospective cohort study of CAP. All hospitalizations within 30 days of study enrollment of patients initially treated as outpatients for CAP were recorded. Two physicians used a set of predetermined definitions to independently categorize the reasons for these subsequent hospitalizations. Thirty-day mortality rate and measures of resolution of pneumonia were assessed. The setting included three university teaching hospitals, a community teaching hospital, and a staff model medical practice within a health maintenance organization.
Results: Of the 944 enrollees with CAP initially treated in the outpatient setting, 71 (7.5%) were subsequently hospitalized within 30 days. The reason for subsequent hospitalization was CAP related in 40 patients and comorbidity related in 26 patients; 5 refused an initial offer of hospitalization. Ninety percent of pneumonia-related hospitalizations occurred within 10 days of initial presentation. Patients who were subsequently hospitalized required a median of 14 days to return to usual activities compared with 6 days for those who were not hospitalized (P<.0001). Patients with a subsequent hospitalization had a higher 30-day mortality rate, 4.2% compared with .3% (P<.01).
Conclusion: A small proportion of patients with CAP initially treated in the outpatient setting are subsequently hospitalized. Such patients face a higher risk of delayed recovery or death. However, the vast majority of outpatients, whether subsequently hospitalized or not, had a successful resolution of their illness. Subsequent hospitalization by 10 days after initial outpatient treatment seems a reasonable screening tool for potentially unsatisfactory quality of care for patients with CAP.