| Methods |
32 sites in USA, Canada and Australia.
Article reports pooled data from two randomized controlled trials with similar protocols.
Six treatment cycles.
Placebo tablets identical in appearance to oral contraceptive pills. |
| Participants |
Healthy women age 14 or more years with regular menses and moderate facial acne.
Excluded recent abnormal cervical cytology; pregnancy; willing to use non‐hormonal contraception if at risk of pregnancy; contraindications to oral contraceptive use; recent oral or injectable hormones; recent use of certain drugs. |
| Interventions |
Levonorgestrel 100 µg and EE 20 µg (N=359) versus placebo (N=362). |
| Outcomes |
Lipoprotein, liver function, blood coagulation, adverse events, body weight, blood pressure. |
| Notes |
|
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Low risk |
Computer‐generated randomization scheme with block size of four stratified by study site. |
| 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 |
High risk |
22 women in the levonorgestrel and 15 women in the placebo group withdrew before starting treatment.
124 in the oral contraceptive and 125 in the placebo group discontinued early or were lost to follow up. Primary reasons for discontinuation described; two women in the levonorgestrel group cited body weight. |
