Background and objective: Studies in respiratory diseases other than chronic obstructive pulmonary disease suggest potentially differing responses to medications among patients from different regions. We report a subgroup analysis of patients recruited to Asian centres from a previously reported 4-year COPD trial.
Methods: Subgroup analysis from a randomized, double-blinded, placebo-controlled trial of tiotropium 18 µg daily in COPD. Primary end-point was rate of decline in FEV(1) . Secondary end-points included spirometry at individual time points, health-related quality of life (St George's Respiratory Questionnaire), exacerbations and mortality.
Results: Of 5992 patients, 362 were from Asian centres (100 from Japan). Mean age 66 years, 95% men, 13% current smokers, BMI: 21 kg/m(2) ; post-bronchodilator FEV(1) : 44% predicted; St George's Respiratory Questionnaire total score: 44 units. No treatment effect was observed for rate of decline in FEV(1) although annual decline was less in Asian patients. Morning pre-bronchodilator FEV(1) and forced vital capacity improved in Asian patients (P < 0.05). Tiotropium reduced number of exacerbations (rate ratio (95% confidence interval (CI)): 0.73 (0.57-0.94)). Hazard ratios (95%CI) for exacerbations and hospitalized exacerbations (tiotropium/control) were 0.81 (0.62-1.05) and 0.85 (0.61-1.19), respectively. St George's Respiratory Questionnaire total score improved by 1.5-6.1 units (P < 0.05 for months 18, 24, 30 and 36) with tiotropium. Fatal events occurred in 34 tiotropium (18.5%) and 42 control (23.6%) patients.
Conclusions: In COPD patients from Asia, tiotropium improves lung function, improves health-related quality of life and reduces exacerbations over 4 years of treatment.
© 2011 The Authors; Respirology © 2011 Asian Pacific Society of Respirology.