Dataset from A Randomised, Double-blind, 8 Treatments, 4 Periods, Incomplete Crossover Study to Determine the Optimal Free Dose Combination of BI 1744 CL and Tiotropium Bromide (Both Delivered by the Respimat® Inhaler) After 4 Weeks Once Daily Treatment in Patients With COPD

The primary objective of this study is to determine the optimum once daily dose of BI 1744 CL and tiotropium in free dose combination (delivered by the Respimat inhaler) after four week treatment in patients with COPD.