Reduced risk of next exacerbation and mortality associated with antibiotic use in COPD

The long-term risk of a subsequent exacerbation of chronic obstructive pulmonary disease (COPD) after treatment with oral corticosteroids without (OS) or with antibiotics (OSA) was compared in a historical general practice-based cohort. Eligible patients were >/=50 yrs of age, had a registered diagnosis of COPD, were on maintenance respiratory drugs, and had experienced at least one exacerbation defined as a prescription OS or OSA. Times to second and third exacerbations were assessed using Kaplan-Meier survival analysis; the risk of a subsequent exacerbation was assessed in a Cox proportional hazards analysis; and all-cause mortality was assessed using Kaplan-Meier survival and Cox proportional hazards analyses. A total of 842 patients had one or more exacerbations. The median time from first to second exacerbation was comparable for the OS and OSA groups, but the time from second to third exacerbation differed: 189 versus 258 days, respectively. The protective effect of OSA was most pronounced during the first 3 months following treatment (hazards ratio 0.72, 95% confidence interval 0.62-0.83). Exposure to antibiotics unrelated to a course of oral corticosteroids almost halved the risk of a new exacerbation. Mortality during follow-up was considerably lower in the OSA group. Adding antibiotics to oral corticosteroids was associated with: reduced risk of subsequent exacerbation, particularly in patients with recurrent exacerbations; and reduced risk of all-cause mortality.