Hänggi 1997.

Methods	Randomised controlled trial
Participants	140 healthy early postmenopausal women between 45 and 55 years of age (mean age 52) with an amenorrhoeic interval >12 months or serum FSH > 30 IU/L. In addition, women > 55 years of age were included if they had a menopausal age < 5 years
Interventions	Tibolone 2.5 mg/d Micronised 17β‐oestradiol, orally 2 mg/d continuously plus sequential dydrogesterone orally 10 mg/d for 14 days every 4 weeks 17β‐oestradiol patch releasing 50 micrograms/d continuously plus sequential dydrogesterone orally 10 mg/d for 14 days every 4 weeks Administered for 24 months
Outcomes	Endometrial hyperplasia, endometrial cancer, breast cancer
Notes	No‐treatment arm with 35 women not considered (as stated in our protocol; moreover they were not randomised) Timing: unclear Location: Switzerland Multi‐centre: not specified
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated list
Allocation concealment (selection bias)	Unclear risk	Not specified
Blinding of participants and personnel (performance bias) All outcomes	High risk	Open trial because women in 1 study arm were treated with an oestrogen patch
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Not specified, but given the nature of outcomes assessed, their evaluation is likely to be "objective"
Incomplete outcome data (attrition bias) All outcomes	High risk	55/105 (after 12 months) and 46/105 (after 24 months) participants were evaluated through endometrial biopsy. Reasons why remaining women were not assessed were not specified
Selective reporting (reporting bias)	Unclear risk	Study protocol not available
Conflict of interest	High risk	Sponsored by the drug manufacturer. Study authors' conflicts of interest not reported