Ergun 2012.

Methods	Randomised controlled trial Number randomised: 58 Failures to receive allocated treatment Losses to follow‐up: 16 Analysis by ITT: no Power calculation: not reported Source of funding: not stated
Participants	Included: women with abnormal uterine bleeding not responding to medical treatment (progesterone, oral contraceptive, NSAIDs etc.) aged over 35, regular menstrual cycle, score of 100 on PBAC Mean age: Not reported Excluded: pregnancy, pelvic infection, uterine abnormality, suspicious endometrial pathology on TVUS
Interventions	Surgical arm: rollerball endometrial ablation (n = 31) Medical arm: LNG‐IUS (n = 27) Actual treatment received: all
Outcomes	Blood loss: PBAC (end scores), satisfaction on a 5‐point scale, need for additional treatment
Notes	—
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Patients were randomised ..."
Allocation concealment (selection bias)	Unclear risk	Method not reported
Blinding (performance bias and detection bias) All outcomes	High risk	Blinding not feasible. Our primary review outcomes are subjective and therefore susceptible to bias related to lack of blinding.
Incomplete outcome data (attrition bias) Primary outcomes	High risk	58 patients randomised (31 in rollerball group and 27 in LNG‐IUS group). 7/31 (22.6%) withdrew from the rollerball group and 9/27 (33%) withdrew from the LNG‐IUS group, so only 72% (42/58) were included in the analysis. These latter numbers were used in the analysis with no method described for analysing missing data.
Selective reporting (reporting bias)	Unclear risk	The authors noted that they investigated adverse effects but these were not adequately reported
Other bias	Unclear risk	Not possible to determine how similar the groups were at baseline; no measure of statistical variation (e.g. SD) reported