Fig. 5From: A systematic review of comparative studies of tiotropium Respimat® and tiotropium HandiHaler® in patients with chronic obstructive pulmonary disease: does inhaler choice matter?a Kaplan–Meier plot for COPD exacerbation in the TIOSPIR® trial. b Corresponding hazard ratio (95% confidence interval) for COPD exacerbation. (Adapted with permission from [48]). CI, confidence interval; COPD, chronic obstructive pulmonary diseaseBack to article page