One-year mortality associated with COPD treatment: A comparison of tiotropium and long-acting beta2-agonists in three Italian regions: Results from the OUTPUL study

Abstract

Purpose: Long-acting bronchodilators, i.e. beta-2-agonists (LABA) and tiotropium are commonly used in COPD treatment. Choice of a specific agent is based on effectiveness and safety. Evidence yields controversial results with respect to mortality. The present study compared one-year mortality associated to treatment with tiotropium versus LABA. Methods: A population-based cohort study using data from Italian health information systems was performed. Patients aged 45+years, discharged with COPD diagnosis in 2006-2009 were identified. Through record linkage with drug claims, patients who received a first prescription of LABA or tiotropium within 6months after discharge were enrolled. The main analysis was restricted to naïve users (no prior use of either LABA or tiotropium). We used 'intention to treat' (ITT) and 'as treated' (AT) approaches. We followed patients for a maximum of 12months. Hazard ratios (HRs) were calculated by Cox regression including quintiles of propensity score. In sensitivity analysis patients receiving tiotropium+LABA combination were included in the tiotropium group. Results: Among the 33891 enrolees, 28% were exposed to Tio, 56% to LABA, 16% to both. Overall mean age was 74years and the mortality rate was 122/1000 person-years (py) at the ITT analysis and 108/1000py at the AT analysis. The adjusted HR for tiotropium only compared with LABA only was 1.06 (95%CI: 0.94-1.20) at the ITT analysis and 1.00 (95%CI: 0.93-1.08) at the AT analysis. Results were robust in sensitivity analysis. Conclusions: In this real-world study use of tiotropium was not associated with an increased risk of one-year mortality compared with LABA.