The Association Between Tiotropium Use And Cardiac Arrhythmia Hospitalization In Patients With Chronic Obstructive Pulmonary Disease Using A Self-Controlled Case Series Design

Abstract

Objectives: Patients with asthma exacerbations requiring inpatient care comprise a subgroup at high risk of adverse asthma-related outcomes. The quality of care in these individuals can thus have substantial impact on the burden of asthma. The purpose of this study was to provide a broad picture on the outcomes associated with different treatment strategies after discharge from an asthma-related admission. MethOds: Using administrative health data of British Columbia, Canada (1997-2012), we created a cohort of individuals discharged from an episode of asthma-related hospitalization. Exposure was assessed in the 60 days after discharge, and was categorized as no controller treatment, monotherapy with inhaled corticosteroids (ICS), or combination therapy with ICS plus long-acting beta agonists (LABA). Safety (re-admission), adherence (proportion of days covered [PDC] with controller medications, and health resource use (asthma-related costs) outcomes were ascertained in the next 365 days. Generalized propensity scores were calculated to achieve balance in the distribution of potential confounders across exposure groups. Results: The final cohort included 1,864; 848; and 954 post-discharge periods, respectively, for no treatment, ICS-only, and ICS+LABA groups. Asthma-related admissions were significantly lower in the ICS-only groups compared with no treatment group (RR= 0.69 [95%CI 0.55-0.87], P= 0.001), but were similar between the ICS+LABA and ICS-only groups (RR= 0.96 [95% CI 0.73-1.27], P= 0.787). The PDC by a controller medication was significantly higher in the ICS group compared with no treatment (difference of 8.7% [95% CI 6.8%-10.5%], P< 0.001), as well as PDC by ICS+LABA compared with PDC by ICS (difference of 7.2% [95%CI 4.7%-9.6%], P< 0.001). There were no differences in costs across the three groups. cOnclusiOns: Initiation of controller medications in the post-discharge period was associated with significant benefits. The higher adherence to controller medication between the ICS+LABA compared with ICS-only group can translate to better outcomes in the long term.