Crosignani 1997.

Study characteristics
Methods	Parallel group, single centre RCT. No. of women randomised: 70 No. of women analysed: 69 Exclusions post randomisation: 0. Losses to follow‐up: 6 months = 0, 12 months = 1 Power calculation for sample size was performed and analysis was by ITT Funding was partially supported by the Italian National Research Council and Leiras Pharmaceuticals provided the intrauterine devices
Participants	Country: Italy Aged 38 to 53 years, all referred for a hysterectomy because of heavy menstrual bleeding Inclusion criteria > 80 mL/cycle loss (as measured by > 100 points on pictorial charts) Negative smear within 12 months Endometrial pathology excluded by transvaginal ultrasound, diagnostic hysteroscopy and endometrial biopsy Uterine size less than 8 weeks Exclusion criteria Abnormal uterine cavity, fibroids greater than 3 cm, or atypical hyperplasia Pregnancy, breast feeding or uncertainty about future fertility Recent use of oestrogens or progestogens (within 3 months) GnRH (within 6 months) Any medication affecting menstrual blood loss concomitant illness Hb < 10 g/dL
Interventions	(1) Levonorgestrel‐releasing (20 ug/day) intrauterine contraceptive system inserted within 7 days of menstruation (2) Endometrial resection in the early proliferative phase using a rollerball and a 90° loop. All the resections were performed by the same surgeon Duration: 12 months. Follow‐up assessments at 6 and 12 months.
Outcomes	Menstrual blood loss by PBAC at 6 and 12 months' follow‐up Hb and serum Fe at 6 and 12 months Participant satisfaction (very satisfied, satisfied, uncertain, dissatisfied) Quality of life (International Quality of Life Assessment Short Form 36 Italian version, release 1.6) Proportion of women with amenorrhoea at 12 months Proportion of women with side effects
Notes	The Academic Department undertaking the study was specifically interested in hysteroscopic surgery and hence the endometrial resection results may be better than those applicable to the general population of clinicians.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "computer‐generated randomisation sequence"
Allocation concealment (selection bias)	Low risk	Quote: "consecutively numbered opaque sealed envelopes"
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not blinded, lack of blinding likely to influence outcome
Blinding of participants and personnel (performance bias) Haematin alkaline, Haemoglobin All outcomes	Unclear risk	Not blinded, lack of blinding unlikely to influence the outcome
Blinding of outcome assessment (detection bias) All outcomes	High risk	Not blinded, lack of blinding likely to influence outcome
Blinding of outcome assessment (detection bias) (Haematine alkaline and haemoglobin) All outcomes	Unclear risk	Not blinded, lack of blinding unlikely to influence the outcome
Incomplete outcome data (attrition bias) All outcomes	Low risk	For primary outcome of menstrual bleeding, 1/70 not included in the analysis. For analysis of PBAC scores, 10/70 not included (5 from each group) and for analysis of quality of life, 8/70 not included (4 in each group). Reasons for attrition were given
Selective reporting (reporting bias)	Low risk	Outcomes clearly specified and reported
Other bias	Low risk	No evidence of an imbalance between groups at baseline