Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
All-cause mortality
[21] Systematic review	17,051 people with COPD 16 RCTs in this analysis	All-cause mortality 2 to 48 months with tiotropium with placebo Absolute numbers not reported	RR 0.97 95% CI 0.86 to 1.09 P = 0.61		Not significant
[24] RCT	555 people aged at least 40 years with COPD	All-cause mortality 9 months 3/266 (1%) with tiotropium 18 micrograms once daily 6/288 (2%) with placebo	Significance not assessed	Effect size not calculated