| Methods |
Two sites in UK and Austria.
One pill‐free cycle, five treatment cycles and one follow‐up cycle. |
| Participants |
Healthy, non‐obese women age 19 to 35 years with demonstrable ovulatory pretreatment cycle.
Excluded heavy smokers; pregnancy; certain diseases; history of migraine with aura; other contraindications for oral contraceptive use. |
| Interventions |
Standard regimen (21 pill days and 7 pill‐free days; N=30) versus prolonged regimen (23 pill days and 5 pill‐free days; N=30). Both groups used the same oral contraceptive (gestodene 75 µg and EE 20 µg). |
| Outcomes |
Follicular development, endogenous hormone levels, cycle control, adverse effects. |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
Randomization list using blocks of ten and four. |
| Allocation concealment (selection bias) |
Unclear risk |
No information |
| Blinding (performance bias and detection bias)
All outcomes |
Low risk |
"Double‐blinded" but did not report who was blinded. |
| Incomplete outcome data (attrition bias)
All outcomes |
Low risk |
One woman in the standard regimen and no women in the prolonged regimen group discontinued early. Primary reasons for discontinuation described and did not include weight change.
No women were lost to follow up. |
