Ref (type)	Population	Outcome, Interventions	Results and statistical analysis	Effect size	Favours
Morbidity
Systematic review	916 people with acute cholecystitis 9 RCTs in this analysis	Morbidity (not further defined) 83/468 (17.7%) with early open cholecystectomy 80/448 (17.9%) with delayed open cholecystectomy	OR 0.95 95% CI 0.66 to 1.38		Not significant
Systematic review	228 people with acute cholecystitis 3 RCTs in this analysis	Morbidity (not further defined) 13/119 (11%) with early laparoscopic cholecystectomy 17/109 (16%) with delayed laparoscopic cholecystectomy	OR 0.69 95% CI 0.27 to 1.73		Not significant
Systematic review	1014 people with acute cholecystitis 10 RCTs in this analysis 6 RCTs included in review	Morbidity (not further defined) with early cholecystectomy (open and laparoscopic) with delayed cholecystectomy (open and laparoscopic) Absolute results not reported	Risk difference −0.06 95% CI −0.17 to +0.06		Not significant
Gastrointestinal upset
RCT	145 people with acute cholecystitis In review Data from 1 RCT	Gastrointestinal upset (diarrhoea, indigestion, and abdominal pain) 1 month after surgery with early cholecystectomy (open or laparoscopic) with delayed cholecystectomy (open or laparoscopic) Absolute results reported graphically	P <0.01	Effect size not calculated	early cholecystectomy
RCT	145 people with acute cholecystitis In review Data from 1 RCT	Gastrointestinal upset (diarrhoea, indigestion, and abdominal pain) 3 months after surgery with early cholecystectomy (open or laparoscopic) with delayed cholecystectomy (open or laparoscopic) Absolute results reported graphically	Reported as not significant P value not reported		Not significant
RCT	145 people with acute cholecystitis In review Data from 1 RCT	Gastrointestinal upset (diarrhoea, indigestion, and abdominal pain) 6 months after surgery with early cholecystectomy (open or laparoscopic) with delayed cholecystectomy (open or laparoscopic) Absolute results reported graphically	Reported as not significant P value not reported		Not significant