Ramezanzadeh 2011.
| Study characteristics | ||
| Methods | Randomised controlled trial Duration and location of the trial: quote: "The study was conducted in the infertility clinic of a tertiary referral centre (Vali‐E‐asr Hospital–Tehran University of Medical Sciences) as a randomized controlled trial, between March 2009 and February 2010.“ |
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| Participants |
Inclusion criteria: women with PCOS with infertility who underwent ovulation induction and timed intercourse for the first time. PCOS was diagnosed by the Rotterdam 2003 criteria. Participants were < 35 years old with at least 1 year of infertility with no other infertility factor. Exclusion criteria: ovarian cysts on cycle day 3 found by transvaginal ultrasound examination. Number of centres: 1, an infertility clinic of a tertiary referral centre Number of women randomised: 80; group A letrozole 5 mg: 40, group B letrozole 7.5 mg: 40 Number of women analysed: group A letrozole 5 mg: 30, group B letrozole 7.5 mg: 37 Number of withdrawals/exclusions/loss to follow‐up and reasons: 4 excluded in group A due to a cyst before treatment, 6 lost to follow‐up in group A and 3 lost to follow‐up in group B Age (y): group A letrozole 5 mg: 28.3 ± 5.0, group B letrozole 7.5 mg: 28.2 ± 4.5 BMI (kg/m²): group A letrozole 5 mg: 25.9 ± 4.2, group B letrozole 7.5 mg: 26.7 ± 3.6 Duration of infertility (y): group A letrozole 5 mg: 3.6 ± 2.3, group B letrozole 7.5 mg: 4.7 ± 3.2 Country: Iran |
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| Interventions |
Group A: letrozole orally given, 5 mg/day for 5 days from cycle days 3‐7 Group B: letrozole orally given, 7.5 mg/day for 5 days from cycle days 3‐7 |
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| Outcomes | Number and size of follicles and endometrial thickness on days 12‐14, the number of days to reach mature follicle, day 7 testosterone level, day 21 progesterone level, ovulation rate, pregnancy rate, miscarriage rate, multiple pregnancy rate, OHSS rate | |
| Notes |
Ethical approval: yes, the hospital research ethics board approved the trial. Informed consent: all participants gave informed consent before inclusion in trial. Source of funding: not stated Conflicts of interest: quote: “Conflict of interest: All of the authors do not have any conflict of interest” Power calculation: quote: "Using PASS software and based on two previous studies, a sample size of 30 subjects in each group would provide 80% power to detect a significant difference in the number of mature follicles and duration of stimulation between two groups with a significant level of 0.05." |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | Participants were randomly allocated using computer‐generated random table into 2 letrozole treatment groups. |
| Allocation concealment (selection bias) | Unclear risk | Not stated |
| Blinding of participants and personnel (performance bias) All outcomes | Unclear risk | Not stated |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Not stated |
| Incomplete outcome data (attrition bias) All outcomes | High risk | 4 participants excluded due to ovarian cyst on day 3 sonography. 9 participants lost to follow‐up, 6 from group A and 3 from group B, without reasons given |
| Selective reporting (reporting bias) | Low risk | All outcomes reported |
| Other bias | Low risk | None |