Doren 1999.

Methods	Randomised double‐blind placebo‐controlled study
Participants	98 healthy postmenopausal women, with intact uterus (mean age 56 years), mean BMI 25 kg/m2, mean time since menopause 6 years
Interventions	Tibolone 2.5 mg/d 17beta‐oestradiol + NETA (2 + 1 mg/d) For 12 months
Outcomes	Unscheduled bleeding
Notes	Timing: unclear Location: Netherlands; single centre Hot flashes and sleeplessness reported as adverse events, each by 1 participant
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Describe: no details on randomisation
Allocation concealment (selection bias)	Unclear risk	Describe: no details given
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Describe: participants blinded but no details on personnel
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Describe: participants recorded bleeding episodes in a diary
Incomplete outcome data (attrition bias) All outcomes	Low risk	Describe: reasons for withdrawal explained
Selective reporting (reporting bias)	Unclear risk	Study protocol not available
Conflict of interest	High risk	Describe: study sponsored by manufacturer of tibolone; employer among study authors