Inhaled anticholinergic use and all-cause mortality among elderly Medicare beneficiaries with chronic obstructive pulmonary disease

BACKGROUND The purpose of this study was to examine the association between use of inhaled anticholinergics and all-cause mortality among elderly individuals with chronic obstructive pulmonary disease (COPD), after controlling for demographic, socioeconomic, health, functional status, smoking, and obesity. METHODS We used a retrospective longitudinal panel data design. Data were extracted for multiple years (2002-2009) of the Medicare Current Beneficiary Survey (MCBS) linked with fee-for-service Medicare claims. Generic and brand names of inhaled anticholinergics were used to identify inhaled anticholinergic utilization from the self-reported prescription medication files. All-cause mortality was assessed using the vital status variable. Unadjusted group differences in mortality rates were tested using the chi-square statistic. Multivariable logistic regressions with independent variables entered in separate blocks were used to analyze the association between inhaled anticholinergic use and all-cause mortality. All analyses accounted for the complex design of the MCBS. RESULTS Overall, 19.4% of the elderly Medicare beneficiaries used inhaled anticholinergics. Inhaled anticholinergic use was significantly higher (28.5%) among those who reported poor health compared with those reporting excellent or very good health (12.7%). Bivariate analyses indicated that inhaled anticholinergic use was associated with significantly higher rates of all-cause mortality (18.7%) compared with nonusers (13.6%). However, multivariate analyses controlling for risk factors did not suggest an increased likelihood of all-cause mortality (adjusted odds ratio 1.26, 95% confidence interval 0.95-1.67). CONCLUSION Use of inhaled anticholinergics among elderly individuals with COPD is potentially safe in terms of all-cause mortality when we adjust for baseline risk factors.