 Blinding Patient and study staff will be blinded to the treatment administration during the 2 study periods. Treatments will consisted, for one treatment period of active Ultibro once a day and placebo Spiriva handihaler, and for the other period of placebo Ultibro once a day and active Spiriva handihaler. Active medication and placebo will be of identical appearance and the order of study medication will be randomized. Pre-package envelopes containing equal quantities of inhaler combination will be numbered and kept in a secure place pharmacy of the hospital or the research site. At the end of the study data collection the blind code will be opened after having completed the primary data analysis. 