Effect of long acting beta agonist therapy on risk of hospitalization in new start COPD patients

Objectives: The objective of this study is to investigate the relative risk of hospitalization among new start COPD patients receiving long-acting beta agonists or short-acting beta agonists (SABA). Methods: Data from a 5% national sample of Medicare enrollees for 2006-2008 were used. New-start COPD patients were defined as patients with no prior COPD therapy for ≥six-months before LABA or SABA initiation, and continuously eligible for parts A, B and D for ≥18 months. Patients enrolled in Medicare Advantage or diagnosed with asthma or younger than 65 years were excluded. Differences in (i) rates of first hospital admissions and (ii) mean number of days to first hospital admission in the six-months following treatment initiation were reported using proportions and t-tests, respectively. In addition, relative risk of hospitalization was estimated using Cox proportional hazards model. Results: From 3,017 COPD patients who met the inclusion criteria, 30% (n=883) were identified as LABA users and 70% (n= 2,134) were SABA users. Overall, 21% (16% in LABA group and 23% in SABA group) patients had an inpatient admission during the follow-up period. Mean days to inpatient admission was 86 for LABA vs. 64 for SABA patients (p-value <0.05). In Cox model, the adjusted relative risk of hospitalization was 0.74 (95%CI = 0.62-0.90) among patients on LABA vs. SABA. Conclusion: The study results suggest new start COPD patients initiating LABA treatment had longer time to hospitalization and had 26% overall lower risk of hospitalization during the 6-months follow-up period compared to those on SABA therapy.