Background: Guidelines for chronic obstructive pulmonary disease (COPD) recommend that treatment choices be based partly on symptoms.
Methods: A post-hoc analysis of pooled data from clinical studies compared the efficacy and safety of once-daily inhaled bronchodilators indacaterol (150 and 300 μg) and open-label tiotropium (18 μg) according to baseline dyspnoea severity on the modified Medical Research Council (mMRC) scale in patients with COPD (mMRC scores <2 = 'less dyspnoea'; scores ≥2 = 'more dyspnoea'). Outcomes were assessed after 26 weeks.
Results: The analysis included 3177 patients. In patients with less dyspnoea: indacaterol (both doses) improved 24-h post-dose ('trough') forced expiratory volume in 1 s (FEV1), transition dyspnoea index (TDI) and St George's Respiratory Questionnaire (SGRQ) total scores at week 26 and reduced the risk of COPD exacerbations vs placebo; and open-label tiotropium improved trough FEV1 and TDI total score vs placebo at week 26. In patients with more dyspnoea: indacaterol (both doses) improved trough FEV1, TDI and SGRQ total scores at week 26; indacaterol 300 μg was the only treatment to improve the TDI total score by more than the minimum clinically important difference (≥1 point) vs placebo; and open-label tiotropium improved trough FEV1, TDI total score at week 26 and decreased the risk of COPD exacerbations vs placebo. In both subgroups, all treatments were well tolerated.
Conclusions: In patients with less dyspnoea, all treatments had similar effects. Indacaterol 300 μg may be a useful treatment option for patients with COPD who experience more severe breathlessness.
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