Table 1.

Characteristics of included randomized controlled trials.

Author	Year	Country	Centers	No. of patients		Inclusion/exclusion criteria	Type of usual medical treatments	Duration, months	Lost to follow up
				LNG-IUS	Medical therapy				LNG-IUS	Medical therapy
Irvine et al. [36]	1998	UK	Single	22	22	Inclusion: parous women aged 18–45 y in good general health with a regular menstrual cycle, a normal pelvic examination with a sound measurement of the uterus of <10 cm, negative cervical cytology and a measured MBL ≥80 ml Exclusion: women had been treated with steroid hormones or anticoagulants during the previous three months, or had used injectable hormones for contraception during the previous 12 months	Norethisterone	3	0	0
Reid et al. [38]	2005	UK	Single	25	26	Inclusion: women aged 18–47 y in good general health with regular, ovulatory, menstrual cycles of 21–35 days and objective, idiopathic menorrhagia (MBL ≥80 ml) Exclusion: women had undiagnosed abnormal bleeding, were anovulatory, had submucous fibroids or fibroids with a total volume of >5 cm3, a uterine sound of >10 cm, abnormal cervical cytology, untreated hypertension, abnormal thyroid or liver function tests, asthma, had been treated for menorrhagia or used hormonal contraceptives within the previous four months	Mefenamic acid	6(6 cycles)†	0	1
Endrikat et al. [18]	2009	Canada	Nine	20	19	Inclusion: healthy women aged 30 at entry, with a diagnosis of idiopathic menorrhagia (PBAC score ≥100 for 2 consecutive cycles) and with a normal or only slightly enlarged uterus Exclusion: contraindications for LNG-IUS and combined oral contraceptive, metabolic and endocrine diseases, diagnostically unclassified genital bleeding, a history of liver or vascular diseases, concomitant use of medications that could influence the study objectives, intramural or subserous fibroids of mean diameter ≥ 4cm or submucous fibroids, adenomyosis or endometrial abnormalities or perimenopausal	Combined oral contraceptive pill	12	3	7
Kaunitz et al. [19]	2010	USA	Fifty-five	82	83	Inclusion: parous women aged ≥18 y with idiopathic heavy menstrual bleeding (MBL ≥80 ml) desiring intrauterine contraception and willing to use barrier contraception if required Exclusion: changes in menstrual regularity, hot flushes, sleeping disorders, or changes in mood within the 3 months preceding the study; breastfeeding; congenital or acquired uterine abnormality, including fibroids if they distorted the uterine cavity or cervical canal; history of organic causes of abnormal uterine; use of LNG-IUS or a copper intrauterine device during the 30 days before the study; history of vascular or coagulation disorders; concomitant use of medication or presence of an underlying disease/condition known to affect the metabolism or pharmacokinetics of the study medication; and a body mass index ≥35 kg/m2	Oral medroxyprogesterone acetate	6 (6 cycles)†	2	1
Shabaan et al. [20]	2011	Egypt	Single	56	56	Inclusion: had self-described heavy menstrual bleeding, requested contraception, aged 20–50 y, had a regular cycle, and were living in a nearby area to make follow-up reasonably possible Exclusion: pregnancy, history of ectopic pregnancy, puerperal sepsis, pelvic inflammatory disease, or evidence of defective coagulation; fibroid of any size; history or evidence of malignancy or hyperplasia in the endometrial biopsy, incidental adnexal abnormality on ultrasound, contraindications to combined oral contraceptive pill, previous endometrial ablation or resection, uninvestigated postcoital bleeding and untreated abnormal cervical cytology	Combined oral contraceptive pill	12	8	9
Gupta et al. [21]	2013	UK	Multiple	285	286	Inclusion: women aged 25–50 y who presented to their primary care physicians with menorrhagia involving at least three consecutive menstrual cycles were eligible to participate Exclusion: women intended to become pregnant over the next 5 years, were taking hormone replacement therapy or tamoxifen, had intermenstrual bleeding or postcoital bleeding or findings suggestive of fibroids or other disorders, or had contraindications to or a preference for either the LNG-IUS or usual medical treatments; women with heavy, irregular bleeding were ineligible unless the results of endometrial biopsy were reported to be normal	Mefenamic acid; tranexamic acid; norethindrone; medroxyprogesterone acetate injection; combined oral contraceptive pill	24	13	16
Küçük et a. [l17]	2008	Turkey	Single	44	44/44‡	Inclusion: perimenopausal patients (age ≥40 y) with heavy menstrual bleeding (MBL ≥80 ml) Exclusion: organic pathology; only irregular bleeding	Depot medroxyprogesterone acetate/oral medroxyprogesterone acetate	6	0	0/0‡
Lähtee-nmäki et al. [37]	1998	Finland	Three	28	28	Inclusion: women who had spontaneous cycles and who were scheduled to undergo hysterectomy for treatment of excessive uterine bleeding with or without dysmenorrhagia Exclusion: had one fibroid ≥3 cm in diameter or more than three uterine fibroids, a history or current clinical evidence or suspicion of malignancy or active liver disease, adnexal tumours or cysts, or pelvic inflammatory disease within the previous 12 months	Mefenamic acid	6	0	0

LNG-IUS – levonorgestrel-releasing intrauterine system; MBL – menstrual blood loss; PBAC – pictorial bleeding assessment chart.

^†6 cycles of treatment with either LNG-IUS or medical therapy;

^‡depot/oral medroxyprogesterone acetate.