NCT01636401.

Methods	Study design: placebo controlled, phase III study Study duration: 12 weeks Study centre and location: Seoul National University Hospital, Republic of Korea Date of study: August 2012 to May 2013
Participants	Inclusion criteria: male or female ≥ 40 years, current or former smokers with a cigarette smoking history of at least 10 pack‐years, diagnosed with stable, moderate to severe COPD as defined by the GOLD (post‐bronchodilator FEV1/FVC ratio < 70% and FEV1 ≥ 30% to < 80% of the predicted value) Exclusion criteria: history of or current asthma, hospitalisation for an acute COPD exacerbation within three months prior to the first visit, any respiratory tract infection or COPD exacerbation in the six weeks before first visit, clinically significant respiratory conditions other than COPD
Interventions	Intervention: inhaled aclidinium bromide 400 μg twice daily Comparison: matching placebo twice daily
Outcomes	Primary outcome: change from baseline in morning predose (trough) FEV1 at week 12 Secondary outcome: change from baseline in peak FEV1 at week 12
Notes	Source of support: Daewoong Pharmaceutical Co Ltd