Sekiba 1992.

Methods	Unit of randomisation: pelvic sidewall Method of randomisation: sealed envelopes Time of randomisation: at completion of surgery Blinding: double 63 participants (126 pelvic sidewalls) No exclusions stated Trial supported by manufacturers of Interceed (Johnson & Johnson Medical, KK, Tokyo, Japan)
Participants	Participants undergoing adhesiolysis by laparotomy N = 63 Dropouts: not stated Indication for surgery: infertility, known presence of bilateral sidewall adhesions Pre‐existing adhesions: yes Cause of adhesions: severe endometriosis 28; previous surgery 15; PID 9; no obvious cause 19 Microsurgery: no Country: Japan Timing and duration: not stated
Interventions	Oxidised regenerated cellulose on pelvic sidewall vs uncovered opposite sidewall Other adjuvants used: none Second‐look laparoscopy Timing: 10 days to 14 weeks after initial surgery Surgeon unaware: yes Adhesiolysis: not stated
Outcomes	Adhesions at second‐look laparoscopy at 10 days to 14 weeks Incidence (per pelvic sidewall) Extent: area, area differential, % improvement Area: measured with sterile ruler Incidence according to size of de‐peritonealised area Incidence according to presence or absence of endometriosis Incidence according to use of sutures Extent (% improvement) according to size of de‐peritonealised area Extent (% improvement) according to presence or absence of endometriosis Extent (% improvement) according to use of sutures Pregnancy outcomes: nil
Notes	Documented with photographs and drawings No power calculations Duplicate publication Supported by Johnson & Johnson Multi‐centre trial Trial also published elsewhere in 1993 (see references)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	No clear statement provided regarding method of randomisation
Allocation concealment (selection bias)	Unclear risk	Sealed envelopes used for allocation concealment but unclear when sealed or opened. Quote: "the pelvic sidewall to be covered was determined randomly using sealed envelopes"
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Unit of randomisation was right or left pelvic sidewall, so every woman also acted as her own control Not clearly stated whether surgeon was blinded, or when treatment allocation was revealed
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Assessor performing second‐look laparoscopy was blinded to allocation
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No mention of whether withdrawals or dropouts occurred during the study
Selective reporting (reporting bias)	Unclear risk	Data presented in graphical form for some outcomes. P values stated for significant outcomes. No data subsets reported. No pregnancy outcomes reported despite being an infertility study
Other bias	Low risk	No other bias identified