Statistical methods
exacerbations, COPD, COPD exacerbations
COPD, COPD EXACERBATION
The analysis was carried out according to the intention‐to‐treat principle. A per‐protocol analysis, excluding participants classed as non‐adherent (<80% of doses taken), was performed to measure sensitivity. The primary clinical outcomes of the number of COPD exacerbations for each subgroup were compared using a negative binomial model with an appropriate dispersion parameter to adjust for inter‐participant variability. Estimates were adjusted for baseline covariates known to be related to outcome: age, smoking index, GOLD stage, number of exacerbations in the previous 1 year, body mass index, and baseline treatment for COPD. The subgroup analyses were undertaken by adding a treatment × variable interaction term to the model using the primary outcome. Analysis was performed using SPSS version 26.0. The clinical subtypes data of the DG and NDG were analyzed with mean ± SD (normal distribution) or median/interquartile (