Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Postoperative outcomes
Systematic review	529 patients who had uncomplicated laparoscopic cholecystectomy 3 RCTs in this analysis	Proportion of people with wound infection 8/261 (3.1%) with drain 1/268 (0.4%) with no drain	OR 5.86 95% CI 1.05 to 32.70 P = 0.04	Large effect size	no drain
Systematic review	68 patients who had uncomplicated laparoscopic cholecystectomy Data from 1 RCT	Proportion of people discharged on same day as treatment 0/33 (0%) with drain 11/35 (31%) with no drain	OR 0.03 95% CI 0 to 0.57 P = 0.02	Large effect size	no drain