Healthcare Resource Utilization, Exacerbations, and Readmissions Among Medicare Patients with Chronic Obstructive Pulmonary Disease After Long-Acting Muscarinic Antagonist Therapy Initiation with Soft Mist versus Dry Powder Inhalers.

Background: Chronic obstructive pulmonary disease (COPD) is often managed with inhaled long-acting muscarinic antagonists (LAMAs), yet real-world data on healthcare resource utilization (HRU) by inhaler type are lacking. This study compared HRU after LAMA initiation with a soft mist inhaler (SMI) versus a dry powder inhaler (DPI). Patients and Methods: Inclusion criteria were COPD diagnosis, age ≥40 years, LAMA initiation (index date = first LAMA SMI or DPI claim 9/1/14-6/30/18), and Medicare Advantage enrollment 1 year pre-index (baseline) to ≥30 days post-index (follow-up). Patients were followed to the earliest of discontinuation, switch, disenrollment, 1 year, or study end (7/31/18). Exclusion criteria were asthma, cystic fibrosis, or lung cancer diagnoses, unavailable demographics, multiple index LAMAs, or baseline LAMA use. Cohorts (SMI or DPI) were balanced on baseline characteristics using inverse probability of treatment weighting. Outcomes included per patient per month (PPPM) COPD-related HRU encounters, and exacerbations (defined as moderate [ambulatory visit with corticosteroid or antibiotic within ±7 days] or severe [emergency visit or inpatient admission]); and 30-day readmissions following COPD-related hospitalizations. Results: After weighting, cohorts (SMI [n=5360] and DPI [n=22,880]) were similar in age (72 and 73 years, respectively), gender (both 52% female), and COPD severity score (31.3 and 31.5, respectively). Cohorts had similar counts of follow-up HRU encounters. However, the SMI cohort had fewer (mean ± standard deviation) COPD-related exacerbations (0.054±0.082 vs DPI cohort 0.059±0.088 PPPM, p<0.001) overall. Moreover, the SMI cohort had fewer severe exacerbations (0.030±0.058 vs DPI: 0.034±0.065 PPPM, p<0.001). Hospitalizations among SMI patients had a lower adjusted odds of readmission versus hospitalizations among DPI patients (odds ratio: 0.656, 95% confidence interval= 0.460, 0.937; p=0.020). Conclusion: SMI initiators had significantly fewer COPD-related exacerbations than DPI initiators. In addition, lower odds of readmissions were observed following COPD-related hospitalizations among the SMI cohort, as compared with the DPI cohort.