Shabaan 2011.

Study characteristics
Methods	Single centre parallel group RCT No. of women randomised: 112 No. of women analysed: 95 (completed 12 months' follow‐up) Power calculation for sample size ‒ 90% power, 15% attrition required 112 participants Authors claimed ITT analysis but no methods used to account for missing data Funding: Bayer Schering Pharma (LNG‐IUS), Proctor & Gamble (sanitary pads) and Assiut University (laboratory work).
Participants	Country: Egypt Women recruited from gynaecology outpatient clinics of Assiut University Hospital, with mean age 39 years Inclusion criteria Self described HMB Requested contraception 20 to 50 years old at initial assessment Regular cycle Living close to hospital for follow‐up Exclusion criteria Pregnancy History of ectopic pregnancy Puerperal sepsis Pelvic inflammatory disease Evidence of defective coagulation History or evidence of malignancy or hyperplasia in the endometrial biopsy Incidental adnexal abnormality on ultrasound, contraindications to COC Previous endometrial ablation/resection Uninvestigated postcoital bleeding Untreated abnormal cervical cytology Fibroids of any size
Interventions	LNG‐IUS Low dose combined oral contraceptive pills (COC) ‒ 30 µg ethinyl estradiol and 150 µg levonorgestrel. Follow‐up at 6 and 12 months.
Outcomes	Primary Reduction of HMB at 12 months (alkaline haematin and PBAC) Secondary Treatment failure Hb and ferritin levels Quality of life (HRQoL questionnaire) Follow‐up at 6 and 12 months
Notes
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote: "Randomization was conducted using a computer generated table of random numbers with allocation concealment"
Allocation concealment (selection bias)	Unclear risk	Not explicitly stated
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	Low risk	No blinding, lack of blinding unlikely to influence 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	Low risk	No blinding, lack of blinding unlikely to influence outcome
Incomplete outcome data (attrition bias) All outcomes	High risk	Substantial loss to follow‐up and bleeding outcomes measured in only 64/112 at 12 months (because of treatment failure)
Selective reporting (reporting bias)	Low risk	All prespecified outcomes reported
Other bias	Low risk	Groups appear comparable at baseline and no other potential bias