Table 4.

Results from sensitivity analyses with data from studies categorised as “high” or “moderate” in quality

Sensitivity analysis	Analysis details	Effect size	Between study variance	Intraclass correlation	Probability of small effect
Between group: oral contraceptive pill withdrawal versus the early follicular phase of the menstrual cycle	22 effect sizes from 9 studies	0.12 [− 0.24–0.43]	0.18 [0.01–0.61]	0.63 [0.0–0.88]	(d ≥ 0.2; p = 0.281; d ≤  − 0.2; p = 0.041)
Between group: oral contraceptive pill consumption versus all phases of the menstrual cycle except the early follicular phase	60 effect sizes from 15 studies	0.14 [− 0.09 to 0.33]	0.22 [0.05–0.48]	0.10 [0.0–0.55]	(d ≥ 0.2; p = 0.282; d ≤  − 0.2; p = 0.006)
Within group: oral contraceptive pill consumption with oral contraceptive pill withdrawal	89 effect sizes from 16 studies	0.03 [− 0.06 to 0.10]	0.04 [0.0–0.16]	0.38 [0.0–0.69]	(|d|≥ 0.2; p < 0.001)

Results are from multilevel random effects models with median parameter estimates and 95% credible intervals (95% CrI)

H high, M moderate, L low, VL very low