Empiric antibiotic therapy anal mortality among Medicare pneumonia inpatients in 10 western states - 1993, 1995, and 1997

Study objectives: To examine the association of empiric inpatient antibioti c treatment of community-acquired pneumonia (CAP) with mortality, and wheth er this association varies from year to year. Design: Population-based, retrospective study adjusting for demographics, c omorbidities, and clinical characteristics. Setting: Acute-care hospitals in 10 western states. Patients: A group of 10,069 Medicare beneficiaries aged greater than or equ al to 65 years who were hospitalized with GAP during fiscal years 1993, 199 5, and 1997, Measurements and results: We examined the risk for mortality during the 30 days after admission to the hospital. The impact of specific antibiotic reg imens varied greatly from year to year. In 1993, therapy with a macrolide p lus a beta -lactam was associated with significantly lower mortality than t herapy with either a beta -lactam alone (adjusted odds ratio [AOR], 0.42; 9 5% confidence interval [CI], 0.25 to 0.69) or other regimens that did not i nclude a macrolide, beta -lactam, or fluoroquinolone (AOR, 0.35; 95% CI, 0. 20 to 0.62), Those associations were not observed in 1995 or 1997. Lower mo rtality was associated with fluoroquinolone monotherapy compared with p-lac tam monotherapy in 1997 (AOR, 0.27; 95% CI, 0.07 to 0.96) and with macrolid e monotherapy compared with other regimens in 1995 (AOR, 0.24; 95% CI, 0.06 to 0.93), but the number of patients who received these regimens was small . Conclusions: The inclusion of a macrolide or a fluoroquinolone in initial e mpiric CAP treatment was associated with improved survival, but this associ ation varied from year to year, perhaps as a result of a temporal variation in the incidence of atypical pathogen pneumonia. Improved testing and surv eillance for atypical pathogen pneumonia are needed to guide empiric therap y.