Diamond 1998.

Study characteristics
Methods	True randomisation (randomisation list) Time of randomisation: preoperative Multi‐centre study: 23 centres in USA Power calculation: no Double‐blinding: yes
Participants	Females 18 years of age and older undergoing laparotomy for gynaecological surgery Exclusion criteria: pregnancy, cancer, PID Number of women randomly assigned: 277 Number of women undergoing second‐look laparoscopy evaluation: 245
Interventions	0.4% hyaluronic acid versus phosphate‐buffered saline as irrigant, not instillant Route of administration: intraperitoneal Dosage/volume: maximum of 1 L of SepraCoat or placebo Second‐look laparoscopy: average of 40 days later
Outcomes	Analysed in review Adhesions present at second‐look laparoscopy Mean adhesion score Other outcomes Mean extent of adhesion score Mean incidence of de novo adhesions at second‐look laparoscopy Mean extent of adhesion score at second‐look laparoscopy. Pregnancy rates: no
Notes	Adhesion scoring system used: own system 0 = no adhesions 1 = up to 25% 2 = 26%‐50% 3 = more than 50%
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Before their initial procedure, patients at each centre were assigned randomly according to a computer‐generated list"
Allocation concealment (selection bias)	Low risk	Quote: "The surgeons who performed the initial procedures, the surgeons who performed the second‐look laparoscopies, and the independent reviewer were blinded to randomisation"
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Initial surgeons were blinded to the solution being used in each woman. Not clearly stated whether women were blinded to allocation.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Quote: "A videotape recording of the abdominopelvic cavity was made at this time [of second‐look laparoscopy]; the video was reviewed later by a blinded, independent reviewer"
Incomplete outcome data (attrition bias) All outcomes	Low risk	No missing outcome data
Selective reporting (reporting bias)	Unclear risk	Data presented in full for all outcomes specified, however no study protocol or trial registry identified for comparison
Other bias	Low risk	Sponsored by Genzyme Corporation