Impact of baseline COPD symptom severity on the benefit from dual mono-bronchodilators: an analysis of the EMAX randomised controlled trial

Rationale: Symptom relief is a key treatment goal in patients with chronic obstructive pulmonary disease (COPD). However, there are limited data available on the response to bronchodilator therapy in patients at low risk of exacerbations with different levels of symptom severity. This study compared treatment responses in patients with a range of symptom severities as indicated by baseline COPD assessment test (CAT) scores. Methods: The 24-week EMAX trial evaluated the benefits of umeclidinium/vilanterol versus umeclidinium or salmeterol in symptomatic patients at low exacerbation risk who were not receiving inhaled corticosteroids. This analysis assessed lung function, symptoms, health status, and short-term deterioration outcomes in subgroups defined by a baseline CAT score [