Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Duration of hospital stay
RCT	70 people at high surgical risk (American Society of Anesthesiologists [ASA] grades II–IV) with acute cholecystitis	Duration of hospital stay 5.3 days with percutaneous cholecystostomy within 8 hours of admission plus early cholecystectomy 15.2 days with medical treatment plus delayed cholecystectomy (8 weeks after full recovery)	P = 0.001	Effect size not calculated	percutaneous cholecystostomy plus early cholecystectomy
Postoperative complications
RCT	70 people with acute cholecystitis	Minor bile leak 1/31 (3%) with percutaneous cholecystostomy plus early cholecystectomy 0/30 (0%) with medical treatment plus delayed cholecystectomy	Significance not assessed
RCT	70 people with acute cholecystitis	Dislodgement of the drainage catheter 1/31 (3%) with percutaneous cholecystostomy plus early cholecystectomy 0/30 (0%) with medical treatment plus delayed cholecystectomy	Significance not assessed