Association of once-daily single-device dual bronchodilators with prevention of rehospitalization for chronic obstructive pulmonary disease: a retrospective national inpatient database study.

Background: Optimal fixed-dose combination (FDC) dual bronchodilators for chronic obstructive pulmonary disease (COPD) are yet to be identified. We aimed to compare outcomes between two types of optimal once-daily FDC dual bronchodilators delivered by a dry powder inhaler (DPI) and soft mist inhaler (SMI).

Methods: Using the Japanese Diagnosis Procedure Combination database, we identified patients with COPD, aged ≥40 years, who were prescribed DPIs or SMIs at discharge from 2015 to 2021. Patients who were prescribed inhaled corticosteroids were excluded. We used inverse probability of treatment weighting (IPTW) to compare COPD-related rehospitalization, outpatient prescription of antibiotics and oral corticosteroids, and cardiovascular event-related rehospitalization between the DPI and SMI groups.

Results: Among 31,145 eligible patients, 18,359 patients were prescribed DPIs, and 12,786, SMIs. After IPTW, there were no differences in the proportions of patients with COPD-related rehospitalization (25.4% vs. 24.7%; P=0.379) or outpatient prescription of antibiotics and oral corticosteroids (7.8% vs. 7.8%; P=0.819) between the groups. The proportion of patients with cardiovascular event-related rehospitalizations was significantly smaller in the DPI group than in the SMI group (4.3% vs. 5.2%; P=0.004). Subgroup analyses showed fewer COPD-related rehospitalizations among patients with Hugh-Jones classification 4-5 in the SMI group than in the DPI group (-2.1%; 95% confidence interval: -4.0% to -0.3%).

Conclusion: No significant difference was found in preventing COPD-related rehospitalization between DPI and SMI use. However, DPI use was associated with fewer cardiovascular event-related rehospitalizations than SMI use. SMI use may be effective in patients with severe dyspnoea.