Prospective observational study of patient-reported outcomes for azithromycin versus usual care in the treatment of bacterial acute exacerbation of chronic bronchitis

Abstract

Background:The 3-day course of azithromycin (AZM) 500 mg/d was introduced to the US market in June 2002. Objective:The objective of this study was to evaluate changes in health-related quality of life (HRQOL) as measured by the St. George's Respiratory Questionnaire (SGRQ) over a 1-month period in patients receiving a 3-day course of AZM for bacterial acute exacerbation of chronic bronchitis (AECB). Methods:This was a prospective, multicenter, observational study evaluating outpatient adults with AECB who received either 3 days of AZM 500 mg/d or 5- to 14-day courses of other antibiotics (usual care [UC]) as directed by the clinician. Patients completed 2 HRQOL instruments—the SGRQ and Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36)—at baseline, day 14, and end of study (EOS) at days 24 to 28. In addition, patients kept a diary for the first 14 days after initiating antibiotic therapy. Results:One hundred twenty-eight patients (57 AZM, 71 UC) were clinically evaluable. There were no significant differences between treatment groups in clinical presentation or baseline demographics, with the exception of a higher percentage of patients with diabetes mellitus in the UC group compared with the AZM group (16.9% vs 3.5%; P = 0.02). Both groups reported similar improvements in signs and symptoms, absenteeism, concomitant respiratory medication use, resource utilization, compliance, and treatment satisfaction as reported in the patient diary. The AZM group reported statistically significant improvement (simple contrasts for end of study vs baseline) in SGRQ measures (total score, P < 0.001; symptoms, P = 0.031; activity, P < 0.001; impacts, P < 0.001) and the SF-36 mental and physical summary components, compared with baseline (both, P < 0.001). Similarly, the UC group reported significant improvement in all SGRQ measures and in the SF-36 physical component score (P < 0.01), but not in the SF-36 mental component score, compared with baseline. At EOS, 80.0% of AZM patients and 59.0% of UC patients had a ≥4-point improvement on the SGRQ total score; however, this difference was not statistically significant in the multivariate analysis. In addition, 89.5% of AZM patients and 89.9% of UC patients were satisfied or very satisfied with their treatment (P = NS). Resource utilization was similar between the groups. Conclusions:In this observational study, patients with AECB treated with a 3-day course of AZM experienced significant improvements in HRQOL as measured by a change of ≥4 points on the SGRQ and SF-36 physical and mental component scores versus baseline.