Table 4.
Adjusted Mean Difference in Cycle Parameters Between Recent Oral Contraceptive Users and Controls
| Outcome | Cycles | n | Mean difference (CI) |
|---|---|---|---|
| Length of luteal phase (days) | 1–2 | 121 | −0.55 (−1.44-0.34) |
| 1–6 | 230 | −0.13 (−1.03-0.78) | |
| Length of menses (days) | 1–2 | 120 | −0.48 (−0.86-−0.11)* |
| 1–6 | 229 | −0.30 (−0.67-0.07) | |
| Length of cycle (days) | 1–2 | 121 | 2.51 (−0.36-5.39) |
| 1–6 | 230 | 3.50 (0.14-6.87)* | |
| Estimated day of ovulation | 1–2 | 121 | 3.00 (0.02-5.97)* |
| 1–6 | 226 | 3.78 (0.27-7.30)* | |
| Menstrual flow scorea | 1–2 | 119 | −1.26 (−1.81-−0.69)** |
| 1–6 | 228 | −1.15 (−1.66-−0.63)** | |
| Cervical mucus scoreb | 1–2 | 120 | −2.36 (−3.64-−1.09)** |
| 1–6 | 225 | −2.17 (−3.28-−1.07)* |
Positive means recent OC users have the larger value or later day.
*
p < 0.05; **p < 0.005.
a
Adjusted for CrMS center of instruction.
b
Adjusted for vitamin use by controls.
CI, confidence interval.