Association between incidence of acute exacerbation and medication therapy in patients with COPD

As exacerbations of chronic obstructive pulmonary disease (COPD) significantly worsen patients' health status and increase disease-related mortality, greater control of exacerbations has important implications for improving patients' health and survival. The incremental benefits of pharmacologic therapies in preventing COPD exacerbations remain unclear. The objective of this observational study was to examine the risk of COPD-related exacerbations between groups of patients receiving inhaled corticosteroids (ICS), anticholinergics (AC), long-acting beta(2)-agonists (LABA), or fixed-dose combinations of ICS and LABA.

A 12-month retrospective cohort analysis of 2923 patients, who were at least 40 years old with the first time COPD in 12 months (i.e., no COPD for 12 months prior to this time) between 2000 and 2004, was conducted using the MarketScan research databases. Patients with at least two prescriptions for ICS, AC, LABA, or ICS + LABA during the observation period were followed from the index prescription date for the duration of the study. COPD-related exacerbations were defined as clinical events in which a primary diagnosis for a respiratory condition had resulted in hospitalization, an emergency room visit, or an outpatient visit followed by a prescription fill of oral corticosteroids or antibiotics within 14 days of the visit. Exacerbation rates were evaluated using a Cox proportional hazard model with adjustment for age, gender, comorbidities, hospitalizations, emergency room visits, and the number of outpatient visits.

Compared with ICS alone, COPD exacerbation rates were 35% (CI:22-42%) lower with ICS + LABA, 32% (CI:13-43%) lower with LABA, and 28% (CI:15-36%) lower with AC. The hazard ratio of the first observed COPD exacerbation was 13-18% lower with the use of bronchodilators, with or without ICS, than with ICS alone. In addition, patients receiving ICS alone experienced more exacerbations during the 12-month period following initiation of therapy than those patients receiving LABA, AC, or ICS + LABA. Generalizability of the results and randomization of treatments were limited due to nature of the administrative claim databases.

The present study found that use of bronchodilators, with or without ICS, in COPD patients resulted in a lower exacerbation rate when compared with ICS monotherapy. Further research is required to understand the clinical effects of specific pharmacologic therapies on COPD exacerbations, as well as their impact on long-term outcomes and costs.