Outpatient treatment of community-acquired pneumonia: evolving trends and a focus on fluoroquinolones.

BACKGROUND Increasing use of broad-spectrum antibiotics in the community, including fluoroquinolones, has been reported, despite concerns for developing antibiotic resistant organisms. Community-acquired pneumonia (CAP) is commonly treated on an outpatient basis, and recent treatment guidelines suggest only a limited role for fluoroquinolones. OBJECTIVES To identify evolving trends in the outpatient treatment of CAP in adults, and to identify factors associated with receipt of a fluoroquinolone. METHODS Retrospective observational design using population-based administrative data. Initial outpatient treatment for subjects diagnosed with CAP between May 1996 and March 2002 was examined. Logistic regression was used to examine the influence of patient characteristics on the receipt of a fluoroquinolone. RESULTS A total of 31,940 outpatients with CAP were identified. The proportion of patients receiving fluoroquinolones increased from 6.6% in 1996/97 to 25.2% in 2001/02. Over the course of the study, 158 (25.9%) of the 610 patients meeting the eligibility criteria for treatment with fluoroquinolones, according to treatment guidelines, received these agents. Of the 31,330 subjects who did not meet the eligibility criterion, 3,886 (12.4%) received a fluoroquinolone. Other variables that influenced the receipt of a fluoroquinolone included: age (for every 10-year increase) [OR=1.16 (1.14-1.19)], urban residence [OR=1.40 (1.30-1.51)], presentation to an emergency department [OR=0.80 (0.70-0.90)], high-level drug use (six or more different drugs in the previous year) [OR=1.50 (1.41-1.59)], and income-level (highest to lowest) [OR=1.20 (1.08-1.35)]. CONCLUSION The use of fluoroquinolones for the treatment of CAP is increasing. However less than 4% of the subjects receiving fluoroquinolones met eligibility requirements according to treatment guidelines. Initiatives to increase the uptake of treatment guidelines appear warranted.