Karimi‐Zarchi 2013.

Study characteristics
Methods	Prospective randomised controlled study Single‐centre
Participants	Country: Iran Population: women with endometrial hyperplasia suffering from abnormal uterine bleeding who referred to Shahid Sadoughi Hospital for treatment Age range 22 to 47 years N = 40 Inclusion criteria: abnormal uterine bleeding due to endometrial hyperplasia confirmed by pathology, women of reproductive age group who intend to preserve their fertility Exclusion criteria: not specified
Interventions	1. LNG‐IUD which releases 20 mcg levonorgestrel per day (n = 20). Treatment duration for 3 months versus 2. Medroxyprogesterone acetate (n = 20). 20 mg daily for 10 days in each menstrual cycle, for 3 months
Outcomes	1. Regression of endometrial hyperplasia. The authors defined this as response to treatment 3 months following treatment (evaluated using vaginal ultrasound and reviewing of pathology reports) Pathological status after treatment (progestational effect, proliferative, atrophic, simple, atypia) Endometrial thickness compared Menstrual conditions of patients compared 2. Adverse effects associated with hormones 3. Satisfaction with treatment
Notes	Recruitment period not specified Funding source not specified Ethics approval not specified No trial registration or study protocol found; searches included the Iranian Registry of Clinical Trials
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Insufficient information: "...patients were randomly divided."
Allocation concealment (selection bias)	Unclear risk	Not specified.
Blinding of participants and personnel (performance bias): EH regression All outcomes	Low risk	No blinding/not possible. As per review protocol: "for subjective measures, if the patients are aware of the type of treatment they are on, and there is no placebo arm to the trial, then we will rate this as at high risk of bias."
Blinding of participants and personnel (performance bias): Other outcomes All outcomes	High risk	For adverse effects and satisfaction. As per review protocol: "for subjective measures, if the patients are aware of the type of treatment they are on, and there is no placebo arm to the trial, then we will rate this as at high risk of bias."
Blinding of outcome assessment (detection bias): EH regression All outcomes	High risk	Not stated. As per review protocol: "if the pathologists reading the slides are aware of the type of treatment the patient is on, or it is not stated whether they are blinded, then we will rate this as at high risk of bias."
Blinding of outcome assessment (detection bias): Other outcomes All outcomes	High risk	No blinding of participants ‒ self‐report.
Incomplete outcome data (attrition bias) All outcomes	Low risk	After randomisation, no missing data.
Selective reporting (reporting bias)	Unclear risk	Primary outcomes listed in the paper's methods were reported in the results. No trial registration or study protocol identified.
Other bias	Unclear risk	Baseline characteristics reported and no obvious significant differences. Discrepancy in table 2 and text on response to treatment data (different denominator).