Pinion 1994.

Study characteristics
Methods	Randomisation, ratio of 2:1:1 (hysterectomy:resection:ablation), by a series of numbered opaque envelopes in a random order Single‐centre, parallel‐group, no blinding Setting: general gynaecology clinic of the Aberdeen Royal Infirmary in Scotland, UK Number of participants randomly assigned: 204 Number of withdrawals: 6 (2 before surgery and 4 refused the allocated treatment) Power calculation for sample size performed and analysis by intention to treat
Participants	Women with mean age 40 years, eligible to undergo hysterectomy for menorrhagia Inclusion criteria: aged < 50 years; weight < 100 kg; clinical diagnosis of dysfunctional uterine bleeding; uterus < 10 weeks of gestational size; normal endometrial histology Exclusion criteria: none reported
Interventions	Treatment 1: laser ablation (1st generation) (53 women) or endometrial resection (TCRE). Women received gonadotrophin releasing hormone agonist analogue (Goserelin) five weeks preoperatively (52 women) Treatment 2: hysterectomy (abdominal (87 women), vaginal (12 women) Duration: 4 years' follow‐up Prior experience of the surgeon not mentioned
Outcomes	Satisfaction rate at 1 and 4 years Change in general health Change in MBL Duration of surgery (minutes) Duration of hospital stay (days) Time to return to work (weeks) Complication rate QoL (Hospital Anxiety and Depression Scale, Golombok Rust Inventory of Marital State) QoL (Psychosocial Adjustment to Illness Scale) – outcome not reported in this review because not enough information provided about categories Health service costs at 1 and 4 years Participant costs at 1 year Requirement for further surgery
Notes	Author contacted for additional data but no reply received. This trial has 4 publications using the same study population and assessing different outcomes. Data usually available only for the laser ablation and endometrial resection combined. Source of funding: Scottish Office Home and Health Dept and ICI (Zeneca) 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)	Low risk	Series of numbered opaque envelopes.
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 unlikely to cause bias.
Selective reporting (reporting bias)	Unclear risk	No prior protocol identified.
Other bias	Unclear risk	Groups appeared balanced at baseline.  Surgeons' previous experience was not reported.