| Methods |
Randomized controlled trial without blinding. The method of randomization is not described in report. Communication with the authors indicated a computer‐generated random allocation sequence. |
| Participants |
1088 women aged 18 to 35 years at 5 sites in Sudan, Sri Lanka, Chile, Ecuador and Dominican Republic. Inclusion criteria were healthy women aged 18 to 35 years who were sexually active and had at least one normal menstrual period since the last pregnancy or the last use of a steroidal contraceptive. Exclusion criteria were contraindications to oral contraceptive use, termination of pregnancy less than 42 days prior to admission if not breastfeeding or termination of pregnancy less than 4 months prior to admission if breastfeeding. Switchers were included in the study. The two groups of participants differed in the complaint dizziness at admission. |
| Interventions |
Triphasic levonorgestrel/ethinylestradiol (50‐75‐125 μg LNG and 30‐40‐30 μg EE in a 6/5/10 days regimen and 7 days of placebo tablets, N=543) [Triquilar] versus
monophasic levonorgestrel/ethinylestradiol (150 μg LNG and 30 μg EE for 21 days and 7 days of placebo tablets, N=545) [Lo‐Femenal]. |
| Outcomes |
Primary outcomes measures are: pregnancy; discontinuation rates and reasons for discontinuation; side effects; cycle control. Use of recall method to collect data on cycle control, side effects and reasons for discontinuation. The report does not describe the definitions of breakthrough bleeding and spotting. Outcome measures cycle control and side effects differ between the various sites. |
| Notes |
The report does not provide an a priori hypothesis or a sample size calculation. Study duration: 12 cycles. 418 women in the triphasic group and 420 women in the monophasic group discontinued early. Reasons for discontinuation are described. The paper reported that 39% of the participants were lost to follow up but provides no breakdown of how many were in each group. The report does not mention withdrawals because of protocol violations. Analysis according to intention‐to‐treat principle. The trial was supported by Family Health International. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Allocation concealment (selection bias) |
Low risk |
Not described in report. Communication with the authors indicated allocation concealment by use of sequentially‐numbered, opaque, sealed envelopes. |
