Objective: To determine the association between outpatient use of oral antibiotics and 30-day all-cause mortality following hospitalization in a group of elderly chronic obstructive pulmonary disease (COPD) patients.
Design: A population-based retrospective cohort study.
Setting: Ontario, Canada.
Population studied: All 26,301 patients, 65 years of age or older, who were hospitalized for COPD between 1992 and 1996 in Ontario.
Methods: All elderly patients admitted at least once with a most responsible diagnosis of COPD using the Canadian Institute for Health Information database were identified. They were then linked to the Ontario Drug Benefit database to determine the use of antibiotics within 30 days of the index hospitalization and to the Ontario registered persons database to determine the 30-day mortality following their index hospitalization.
Results: Outpatient use of antibiotics within 30 days before the index hospitalization was associated with a significant reduction in the 30-day mortality following hospitalization (odds ratio [OR] 0.83, 95% CI 0.75 to 0.92). Use of macrolides had the lowest relative odds for mortality (OR 0.58, 95% CI 0.47 to 0.73), while use of fluoroquinolones had the highest relative odds (OR 0.98, 95% CI 0.84 to 1.15).
Conclusions: Use of antibiotics before hospitalization was associated with a significant reduction in the risk of short term mortality among a group of elderly COPD patients who eventually required hospitalization for their disease. These findings support the early use of antibiotics in COPD patients who experience an acute exacerbation.