Duleba 2003.

Methods	Multi‐centre (10), parallel prospective randomised design Timing: not specified
Participants	279 women randomised; aged 30 to 50 years (mean EC 41.2 (5.1) and RBE 41.1 (4.8)); recruited from university and private medical centres in the USA Inclusion criteria: Menorrhagia due to benign causes Good general health Documented history of excessive uterine bleeding for at least 3 months Failed traditional therapy Did not desire future fertility PBAC > 150 Exclusion criteria: Uterine volume > 300 mL Uterine cavity sounding > 10 cm Clotting deficit or bleeding disorders Active pelvic inflammatory disease Abnormal cervical cytology within 1 year History of gynaecological malignancy within 5 years Intramural myomas > 2 cm, submucous myomas, or endometrial polyps Septate uterus Previous endometrial ablation or other surgery in which thinning of the uterine wall may occur Malignant pathology or hyperplasia Pregnancy
Interventions	Endometrial cryoablation (n = 193) Rollerball electro‐ablation (n = 86)
Outcomes	Menstrual diaries 1 cycle before and 12 months after PBAC Bleeding Pain Mood PMS QOL ‐ Dartmouth COOP assessment questionnaire Anaesthesia Adverse outcomes Satisfaction
Notes	Power calculation performed; study authors did not state intention‐to‐treat analysis Funding: Cryogen Inc. (Duleba, Soderstrom, and Townsend all consultants to Cryogen Inc.) Conflicts of interest: not reported "those randomised to cryoablation had significantly worse menorrhagia"
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Method not reported
Allocation concealment (selection bias)	Unclear risk	Sealed envelopes but no other details of how allocation was concealed
Blinding of participants and personnel (performance bias) All outcomes	High risk	Unlikely
Blinding of outcome assessment (detection bias) All outcomes	High risk	Unlikely
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	51/279 (18%) dropouts for outcomes measured at 12 months ‐ no reasons given nor details on distribution per group
Selective reporting (reporting bias)	Low risk	All prespecified outcomes reported
Other bias	Unclear risk	Participants receiving cryoablation had higher PBAC scores at baseline; study authors were consultants for the medical equipment company that provided funding for cryoablation