A randomized controlled trial to assess the efficacy of tiotropium in Canadian patients with chronic obstructive pulmonary disease

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) who smoke have a greater annual rate of decline in forced expiratory volume in 1s (FEV1) than those patients who have stopped smoking. OBJECTIVES: To assess the effect of titropium on pre-dose (trough) FEV1 in patients with COPD followed in Canada. METHODS: A total of 913 patients were randomly assigned to receive either tiotropium 18 mu g once daily (n=608) or placebo (usual care minus inhaled anticholinergics) (n=305) for 48 weeks in the present randomized, double-blind, parallel-group study. The effect of tiotropium on measurements of lung function (FEV1, FEV6 and forced vital capacity), symptoms, health-related quality of life (St George's Respiratory Questionnaire) and exacerbations were examined. RESULTS: Tiotropium improved trough FEV1 in both current and ex-smokers compared with placebo. Baseline FEV1 in smokers and ex-smokers was 1.03 L and 0.93 L, respectively (P<0.001). At week 48, the mean difference between the tiotropium and placebo groups was 0.14 +/- 0.04 L (P<0.001) in the ex-smoker group. Tiotropium also significanly improved trough forced vital capacity and FEV6 compared with placebo throughout the treatement significantly improved the St George's Respiratory Questionnaire total score compared with placebo at week 48 (40.9 versus 43.7 units, P<0.005). CONCLUSIONS: Compared with the placebo group, tiotropium provides sustained improvements in lung function in patients with COPD, with improvements for smokers and ex-smokers.