| Methods |
100 sites in USA and 10 in Canada.
First 1/3 of participants were to have 13 treatment cycles and the remaining 2/3 were to have 6 treatment cycles.
Allocated in block sizes of 11; blinded. |
| Participants |
Sexually active, healthy women aged 18 to 45 years at risk for pregnancy with regular menses.
Excluded recent pregnancy; recent lactation; contraindications to oral contraceptives; certain diseases; smokers aged 35 or more years; certain drugs or devices; recent DMPA use; and recent alcohol or substance abuse. |
| Interventions |
EE 20 µg and norethindrone acetate 1.0 mg with 75 mg ferrous fumarate on days 22‐28 (N=853 for 6 cycles / 318 for 13 cycles) versus EE 25 µg and norgestimate 180‐215‐250 µg (N=1236 for 6 cycles / 487 for 13 cycles). |
| Outcomes |
Contraceptive efficacy, cycle control, and safety.
'Breakthrough' bleeding or spotting defined as bleeding or spotting that occurred during active pill days unless contiguous with menses.
'Amenorrhea' defined as two consecutive cycles without any bleeding or spotting.
Secondary report (Burkman 2007) included weight change.
Secondary report (Hampton 2009) re‐analyzed bleeding data with new criteria (Mishell 2007b); unscheduled bleeding data presented here. |
| Notes |
Cyclophasic regimens discontinued early and not reported.
74% (2130/2894) completed study. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Allocation concealment (selection bias) |
Unclear risk |
Allocation concealment methods not reported. |
