Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Need for rescue bronchodilators
[18] RCT 3-armed trial	780 people	Need for rescue medication with ipratropium (40 micrograms 4 times daily) with placebo Absolute results not reported	P = 0.15 (ipratropium v placebo)		Not significant
Symptoms
[18] RCT 3-armed trial	780 people	Symptoms with ipratropium (40 micrograms 4 times daily) with placebo Absolute results not reported	P = 0.44 (ipratropium v placebo)		Not significant