Response to: Letter to the Editor Regarding “Comparative Effectiveness of FF/1 UMEC/VI and BUD/GLY/FORM in Patients with COPD Stepping Up From Dual Therapy”

We thank Quint et al. [1] for their interest in our recent article describing comparative real-world effectiveness of single-inhaler triple therapies (SITTs) in patients with COPD stepping up from dual therapy [2], and welcome the opportunity to respond to the points raised in their letter on the limitations and technical complexities of our analyses.The letter highlights two areas to be considered when interpreting our comparative effectiveness results.The first is the inherent limitations associated with use of open claims data.We agree that lack of direct verification of insurance eligibility, inclusion of overlapping records, inconsistent capture of encounters, and incomplete longitudinal follow-up are limitations of open claims data, and have highlighted these in the Methods and Discussion sections of our paper.However,