Gannon 1991.

Study characteristics
Methods	Randomisation by sealed envelope Single‐centre, parallel‐group, no blinding Setting: Royal Berkshire Hospital in Reading, UK Number of women randomly assigned: 54 Number of withdrawals: 3 (1 from the resection group who wanted hysterectomy, 1 from the hysterectomy group who wanted resection, and 1 from the hysterectomy group who postponed surgery and was treated elsewhere) Power calculation and intention‐to‐treat analysis not reported
Participants	Women with median age 40 years awaiting abdominal hysterectomy for menorrhagia Exclusion criteria: leiomyomata; endometrial or cervical neoplasia; concomitant ovarian pathology, PID or endometriosis
Interventions	Treatment 1: endometrial resection (TCRE): 25 women Treatment 2: abdominal hysterectomy: 26 women Duration: mean 12 months' follow‐up Procedures performed by 'experienced surgeons on routine operating lists' Endometrial resection group given an intramuscular injection of medroxyprogesterone acetate 150 mg 4–6 weeks before surgery to reduce endometrial thickness.
Outcomes	Change in MBL Duration of surgery (minutes) Duration of hospital stay (days) Time to return to work (weeks) Postoperative complications Requirement for further surgery Resource cost of surgery (theatre and ward) (per woman)
Notes	Author contacted but no reply received. Source of funding: not reported. No information stated regarding trial registration
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomisation sequence not described.
Allocation concealment (selection bias)	Unclear risk	Sealed envelope but no other safeguards described.
Blinding (performance bias and detection bias) All outcomes	High risk	Not feasible for a comparison of surgical techniques.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Dropouts minimal and not likely to cause bias.
Selective reporting (reporting bias)	Unclear risk	No prior protocol identified.
Other bias	Low risk	Groups appeared balanced at baseline, although very few parameters examined.