The Impact of Statin Drug Use on All-Cause Mortality in Patients With COPD: A Population-Based Cohort Study

Abstract

Background: Patients with COPD are often prescribed statin drugs due to the increased prevalence of cardiovascular disease. There is considerable debate about the benefits conferred by statin drugs in patients with COPD. This study evaluates the association of statin drug use with all-cause and lung-related mortality in patients with COPD.

Methods: This study uses population-based administrative data for the province of British Columbia, Canada. A cohort of patients with COPD was identified based on individual patient prescription records. Statin drug exposure was ascertained in the 1-year period after the COPD diagnosis. The primary and secondary outcomes, all-cause and lung-related mortality, respectively, were evaluated in the 1-year period thereafter using multivariate Cox proportional hazards models and several definitions of medication exposure.

Results: There were 39,678 patients with COPD that met the study inclusion criteria. Of them, 7,775 (19.6%) had received at least one statin drug dispensed in the exposure ascertainment window. There were 1,446 all-cause deaths recorded in the cohort in the 1-year period after exposure ascertainment. In multivariate analysis, the estimated hazard ratio (HR) for statin drug exposure was 0.79 (95% CI, 0.68-0.92; P = .0016), suggesting a 21% reduction in the risk from statin drug use on all-cause mortality. For lung-related mortality, there was also a considerable reduction in the risk for all-cause mortality from statin drug use (HR, 0.55; 95% CI, 0.32-0.93; P = .0254). These results were robust to different specifications of the exposure ascertainment window.

Conclusions: This study shows that statin drug use in a population-based cohort of patients with COPD may confer benefits regarding reduced lung-related and all-cause mortality.

Keywords: COPD; mortality; pharmacoepidemiology; statins.