Comparison 18.

Levonorgestrel single dose versus split dose

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Observed number of pregnancies (all women)	3	6653	Risk Ratio (M‐H, Fixed, 95% CI)	0.84 [0.53, 1.33]
2 Observed number of pregnancies (by risk status)	1	2712	Risk Ratio (M‐H, Fixed, 95% CI)	0.83 [0.46, 1.49]
2.1 High‐risk women	1	792	Risk Ratio (M‐H, Fixed, 95% CI)	0.56 [0.22, 1.41]
2.2 Low‐risk women	1	1920	Risk Ratio (M‐H, Fixed, 95% CI)	1.10 [0.51, 2.40]
3 Observed number of pregnancies (time from intercourse)	2	5489	Risk Ratio (M‐H, Fixed, 95% CI)	0.95 [0.57, 1.57]
3.1 Within 72 h	2	4873	Risk Ratio (M‐H, Fixed, 95% CI)	0.86 [0.48, 1.54]
3.2 Later than 72 h	2	616	Risk Ratio (M‐H, Fixed, 95% CI)	1.26 [0.46, 3.43]
4 Specific side effects	3		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
4.1 Nausea	3	6804	Risk Ratio (M‐H, Fixed, 95% CI)	0.97 [0.88, 1.07]
4.2 Vomiting	3	6804	Risk Ratio (M‐H, Fixed, 95% CI)	1.01 [0.83, 1.22]
4.3 Headache	3	6804	Risk Ratio (M‐H, Fixed, 95% CI)	1.14 [1.01, 1.30]
4.4 Dizziness	3	6804	Risk Ratio (M‐H, Fixed, 95% CI)	0.91 [0.79, 1.05]
4.5 Fatigue	2	5742	Risk Ratio (M‐H, Fixed, 95% CI)	1.01 [0.88, 1.15]
4.6 Breast tenderness	2	3782	Risk Ratio (M‐H, Fixed, 95% CI)	1.12 [0.91, 1.37]
4.7 Diarrhoea	1	2720	Risk Ratio (M‐H, Fixed, 95% CI)	1.21 [0.81, 1.79]
4.8 Spotting/bleeding after treatment	1	2720	Risk Ratio (M‐H, Fixed, 95% CI)	1.00 [0.90, 1.12]
4.9 Lower abdominal pain	2	3782	Risk Ratio (M‐H, Fixed, 95% CI)	0.90 [0.77, 1.05]
4.10 Heavy menses	1	1062	Risk Ratio (M‐H, Fixed, 95% CI)	1.48 [1.08, 2.04]
5 Menses	2		Risk Ratio (M‐H, Fixed, 95% CI)	Subtotals only
5.1 Early	1	1118	Risk Ratio (M‐H, Fixed, 95% CI)	0.67 [0.54, 0.82]
5.2 Delay	2	3784	Risk Ratio (M‐H, Fixed, 95% CI)	1.18 [0.96, 1.46]