Comparison 3.

Smoking cessation interventions: health education vs usual care

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Abstinence in late pregnancy	3	374	Risk Ratio (M-H, Random, 95% CI)	1.51 [0.64, 3.59]
1.1 Single interventions	2	229	Risk Ratio (M-H, Random, 95% CI)	1.29 [0.49, 3.42]
1.2 Multiple interventions	1	145	Risk Ratio (M-H, Random, 95% CI)	4.06 [0.46, 35.41]
2 Abstinence in late pregnancy: biochemically validated only	2	229	Risk Ratio (M-H, Random, 95% CI)	1.29 [0.49, 3.42]
2.1 Single interventions	2	229	Risk Ratio (M-H, Random, 95% CI)	1.29 [0.49, 3.42]
3 Mean cigarettes per day in late pregnancy	2		Std. Mean Difference (IV, Random, 95% CI)	Subtotals only
3.1 Single interventions	1	552	Std. Mean Difference (IV, Random, 95% CI)	−0.72 [−0.89, −0.55]
3.2 Multiple interventions	1	135	Std. Mean Difference (IV, Random, 95% CI)	−0.32 [−0.66, 0.02]