Fig. 4From: The effect of delaying initiation with umeclidinium/vilanterol in patients with COPD: an observational administrative claims database analysis using marginal structural modelsComparison of HR by UMEC/VI initiation month (a) with and (b) without time interaction term. CI, confidence interval; HR, hazard ratio; UMEC/VI, umeclidinium/vilanterolBack to article page