| Methods |
Randomized controlled trial without blinding. The method of randomization was not described. Communication with the authors indicated randomization by use of a random number table. |
| Participants |
477 women at sites in the U.S.A. Inclusion criteria were women aged 18 years or older. Exclusion criteria were contraindications to oral contraceptive use. Little information about baseline demographics. All participants were first‐time oral contraceptive users. |
| Interventions |
Triphasic norethindrone/ethinylestradiol (500‐750‐1000 μg NET and 35 μg EE in a 7/7/7 days regimen and 7 days of placebo tablets) [Ortho‐Novum 7/7/7] versus
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) [Triphasil] versus
monophasic norethindrone/ethinylestradiol (1000 μg norethindrone and 35 μg ethinylestradiol for 21 days and 7 days of placebo tablets) [Ortho‐Novum 1/35]. |
| Outcomes |
Outcome measures are: side effects; cycle control; continuation rate; satisfaction; side effects after change of OC. Use of recall method to collect data on cycle control, side effects and satisfaction with the method. Breakthrough bleeding was defined as any spotting or bleeding between menstrual periods, and amenorrhea as the absence of spotting or bleeding during the expected time of the menstrual period. Limited information on outcome measures. |
| Notes |
The report does not provide an a priori hypothesis or a sample size or power calculation. Study duration: 12 cycles. 100 women discontinued early, however the paper does not provide a breakdown of the number in each group. No information on reasons for discontinuation. Analysis not according to intent‐to‐treat principle. The report contains no references to other studies. The trial was conducted by Planned Parenthood Federation of America. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Allocation concealment (selection bias) |
High risk |
Not described in report. Communication with the authors indicated no concealment of treatment allocation. |
