Herman 2013.

Study characteristics
Methods	Randomized controlled trial
Participants	Women with HMb Over 34 years Without intracavitary pathology Not planning future pregnancy
Interventions	Bipolar endometrial ablation (Novasure®) = 138 LNG‐IUS (Mirena®) = 132
Outcomes	PBAC at 24 months Re‐intervention Satisfaction Quality of life Sexual function
Notes	Short communication of results; full trial awaiting publication. Authors contacted for further details. This study is funded by The Netherlands Organisation for Health Research and Development (ZonMW) grant. The authors declare that they have no competing interests Between July 2012 and December 2015
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	"Randomisation will be performed by accessing a web‐based randomisation programme; patients will be randomised into two groups in a ratio of 1:1, using permuted block randomizations with a variable block size". (protocol)
Allocation concealment (selection bias)	Low risk	"Participants will be given a computer generated numeric code. Data handling will be done anonymously, with the patient code only available to the local investigator and the research nurse working in the local centre" (protocol)
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding highly unlikely, lack of blinding likely to influence outcome
Blinding of participants and personnel (performance bias) Haematin alkaline, Haemoglobin All outcomes	Unclear risk	Alkaline haematin and haemoglobin were not measured
Blinding of outcome assessment (detection bias) All outcomes	High risk	Blinding highly unlikely, lack of blinding likely to influence outcome
Blinding of outcome assessment (detection bias) (Haematine alkaline and haemoglobin) All outcomes	Unclear risk	Alkaline haematin and haemoglobin were not measured
Incomplete outcome data (attrition bias) All outcomes	High risk	91% completed 24 months' follow‐up
Selective reporting (reporting bias)	High risk	Some of the outcomes on the protocol are not included on the trial report (complications, sick leave and costs)
Other bias	Unclear risk	No information about baseline characteristics, conflict of interest or funding