Comparison 2.

Smoking cessation interventions: counselling vs less intensive intervention

Outcome or subgroup title	No. of studies	No. of participants	Statistical method	Effect size
1 Abstinence in late pregnancy	16	5247	Risk Ratio (M-H, Random, 95% CI)	1.35 [1.00, 1.82]
1.1 Single interventions	5	735	Risk Ratio (M-H, Random, 95% CI)	1.51 [0.90, 2.54]
1.2 Multiple interventions	10	4260	Risk Ratio (M-H, Random, 95% CI)	1.23 [0.84, 1.78]
1.3 Tailored interventions	1	252	Risk Ratio (M-H, Random, 95% CI)	2.39 [1.03, 5.56]
2 Abstinence in late pregnancy: biochemically validated only	12	2858	Risk Ratio (M-H, Random, 95% CI)	1.46 [1.15, 1.85]
2.1 Single interventions	5	735	Risk Ratio (M-H, Random, 95% CI)	1.51 [0.90, 2.54]
2.2 Multiple interventions	6	1871	Risk Ratio (M-H, Random, 95% CI)	1.38 [1.05, 1.80]
2.3 Tailored interventions	1	252	Risk Ratio (M-H, Random, 95% CI)	2.39 [1.03, 5.56]
3 Continued abstinence (relapse prevention) in late pregnancy (spontaneous quitters)	4	692	Risk Ratio (M-H, Random, 95% CI)	1.05 [0.98, 1.13]
3.1 Single interventions	2	204	Risk Ratio (M-H, Random, 95% CI)	1.02 [0.88, 1.18]
3.2 Multiple interventions	2	488	Risk Ratio (M-H, Random, 95% CI)	1.06 [0.96, 1.17]
3.3 Tailored interventions	0	0	Risk Ratio (M-H, Random, 95% CI)	0.0 [0.0, 0.0]
4 Abstinence at 0 to 5 months postpartum	6	1980	Risk Ratio (M-H, Random, 95% CI)	1.17 [0.82, 1.66]
4.1 Single interventions	1	82	Risk Ratio (M-H, Random, 95% CI)	0.63 [0.11, 3.60]
4.2 Multiple interventions	4	1646	Risk Ratio (M-H, Random, 95% CI)	1.19 [0.99, 1.43]
4.3 Tailored interventions	1	252	Risk Ratio (M-H, Random, 95% CI)	12.80 [1.70, 96.35]
5 Abstinence at 6 to 11 months postpartum	3	1271	Risk Ratio (M-H, Random, 95% CI)	1.08 [0.83, 1.40]
5.1 Single interventions	1	105	Risk Ratio (M-H, Random, 95% CI)	2.45 [0.50, 12.08]
5.2 Multiple interventions	2	1166	Risk Ratio (M-H, Random, 95% CI)	1.05 [0.80, 1.38]
6 Abstinence at 12 to 17 months postpartum	2	1188	Risk Ratio (M-H, Random, 95% CI)	1.25 [0.71, 2.20]
6.1 Multiple interventions	2	1188	Risk Ratio (M-H, Random, 95% CI)	1.25 [0.71, 2.20]
7 Reduction in late pregnancy: self-reported > 50%	2	1235	Risk Ratio (M-H, Random, 95% CI)	1.35 [1.07, 1.71]
7.1 Multiple interventions	2	1235	Risk Ratio (M-H, Random, 95% CI)	1.35 [1.07, 1.71]
8 Reduction in late pregnancy: biochemically validated	2	758	Risk Ratio (M-H, Random, 95% CI)	1.35 [0.98, 1.87]
8.1 Multiple interventions	2	857	Risk Ratio (M-H, Random, 95% CI)	1.35 [0.98, 1.87]
9 Mean cigarettes per day in late pregnancy	2	397	Std. Mean Difference (IV, Random, 95% CI)	−0.11 [−0.30, 0.09]
9.1 Single interventions	1	121	Std. Mean Difference (IV, Random, 95% CI)	0.01 [−0.34, 0.37]
9.2 Multiple interventions	1	276	Std. Mean Difference (IV, Random, 95% CI)	−0.16 [−0.40, 0.08]
10 Low birthweight infants (< 2500 g)	2	305	Risk Ratio (M-H, Random, 95% CI)	0.58 [0.32, 1.04]
10.1 Single interventions	1	227	Risk Ratio (M-H, Random, 95% CI)	0.55 [0.25, 1.21]
10.2 Multiple interventions	1	276	Risk Ratio (M-H, Random, 95% CI)	0.61 [0.25, 1.50]
11 Preterm births	3	794	Risk Ratio (M-H, Random, 95% CI)	0.82 [0.47, 1.42]
11.1 Single interventions	1	227	Risk Ratio (M-H, Random, 95% CI)	0.55 [0.25, 1.21]
11.2 Multiple interventions	1	308	Risk Ratio (M-H, Random, 95% CI)	1.17 [0.46, 2.95]
11.3 Tailored interventions	1	952	Risk Ratio (M-H, Random, 95% CI)	1.30 [0.30, 5.71]
12 Mean birthweight	3	546	Mean Difference (IV, Random, 95% CI)	56.02 [−31.46, 143. 50]
12.1 Single interventions	1	227	Mean Difference (IV, Random, 95% CI)	57.00 [−93.50, 207. 50]
12.2 Multiple interventions	2	319	Mean Difference (IV, Random, 95% CI)	76.01 [−88.59, 240. 61]