| Explanatory variable |
k (n)1 |
RR2
|
(95% CI) |
RoRR3
|
(95% CI) |
P value |
Adjusted R2 %4
|
I2% (Res)5
|
Overall model P value6
|
| 1.2.1a Main intervention strategy |
|
|
|
|
10% |
41% |
0.113 |
| Counselling (reference) |
51 (18,267) |
1.31 |
(1.16, 1.48) |
1.00 |
|
|
|
|
|
| Health education |
11 (2142) |
1.26 |
(0.94, 1.69) |
0.96 |
(0.70, 1.32) |
0.813 |
|
|
|
| Feedback |
6 (859) |
1.91 |
(1.22, 3.00) |
1.46 |
(0.91, 2.33) |
0.111 |
|
|
|
| Incentives |
12 (1708) |
1.84 |
(1.34, 2.53) |
1.41 |
(1.00, 1.98) |
0.051 |
|
|
|
| Social Support |
13 (2488) |
1.19 |
(0.94, 1.50) |
0.91 |
(0.69, 1.18) |
0.459 |
|
|
|
| 1.2.1b Focus of the intervention |
|
|
|
|
|
|
5% |
40% |
0.041 |
| Mental Health (reference) |
10 (2411) |
1.07 |
(0.85, 1.36) |
1.00 |
|
|
|
|
|
| Smoking cessation |
84 (23,847) |
1.40 |
(1.27, 1.55) |
1.30 |
(1.01, 1.68) |
0.041 |
|
|
|
| 1.2.2 Comparison type |
|
|
|
|
|
|
‐9% |
44% |
0.421 |
| Usual care (reference) |
46 (15,782) |
1.41 |
(1.22, 1.62) |
1.00 |
|
|
|
|
|
| Alternative intervention |
6 (500) |
1.62 |
(1.06, 2.48) |
1.16 |
(0.74, 1.81) |
0.522 |
|
|
|
| Less intensive |
43 (10,170) |
1.27 |
(1.11, 1.46) |
0.91 |
(0.74, 1.11) |
0.329 |
|
|
|
| 1.2.3a Intensity: frequency of contact |
|
|
|
|
‐1% |
42% |
0.184 |
| Single contact at time of routine pregnancy care (reference) |
8 (1422) |
1.90 |
(1.24, 2.89) |
1.00 |
|
|
|
|
|
| Single contact, outside of routine pregnancy care |
15 (5010) |
1.11 |
(0.86, 1.43) |
0.59 |
(0.36, 0.96) |
0.033 |
|
|
|
| 2‐5 contacts at time of care |
8 (2811) |
1.73 |
(1.21, 2.48) |
0.91 |
(0.52, 1.59) |
0.742 |
|
|
|
| 2‐5 contact outside routine care |
18 (6338) |
1.23 |
(1.01, 1.51) |
0.65 |
(0.41, 1.04) |
0.071 |
|
|
|
| > 5 contact at time of care |
10 (2081) |
1.36 |
(1.00, 1.84) |
0.72 |
(0.43, 1.20) |
0.206 |
|
|
|
| > 5 contact outside of care |
35 (8596) |
1.38 |
(1.19, 1.60) |
0.73 |
(0.47, 1.14) |
0.164 |
|
|
|
| 1.2.3b Intensity: duration of contact |
|
|
|
|
‐3% |
37% |
0.155 |
| < 15 mins (reference) |
8 (1422) |
1.26 |
(1.00, 1.58) |
1.00 |
|
|
|
|
|
| 15 ‐ 44 mins |
15 (5010) |
1.53 |
(1.22, 1.93) |
1.22 |
(0.88, 1.68) |
0.229 |
|
|
|
| 45 mins ‐ < 2 hrs |
8 (2811) |
1.27 |
(1.05, 1.53) |
1.01 |
(0.75, 1.35) |
0.962 |
|
|
|
| 2 hrs ‐ < 5 hrs |
18 (6338) |
1.14 |
(0.90, 1.44) |
0.91 |
(0.66, 1.26) |
0.556 |
|
|
|
| 5 hrs ‐ < 8 hrs |
10 (2081) |
1.27 |
(0.91, 1.77) |
1.01 |
(0.67, 1.51) |
0.967 |
|
|
|
| ≥ 8 hrs |
35 (8596) |
1.74 |
(1.36, 2.23) |
1.38 |
(0.99, 1.93) |
0.058 |
|
|
|
| 1.2.4a Use of self‐help manuals |
|
|
|
|
|
|
‐1% |
39% |
0.341 |
| No (reference) |
54 (11,447) |
1.33 |
(1.16, 1.52) |
1.00 |
|
|
|
|
|
| Yes |
30 (11,202) |
1.48 |
(1.25, 1.74) |
1.11 |
(0.90, 1.37) |
0.341 |
|
|
|
| 1.2.4b Use of telephone support |
|
|
|
|
‐6% |
40% |
0.869 |
| No (reference) |
75 (21,928) |
1.36 |
(1.22, 1.51) |
1.00 |
|
|
|
|
|
| Yes |
20 (4524) |
1.33 |
(1.09, 1.62) |
0.98 |
(0.78, 1.23) |
0.869 |
|
|
|
| 1.2.5 Social economic status |
|
|
|
|
|
|
|
|
|
| Not low (reference) |
29 (8417) |
1.39 |
(1.19, 1.63) |
1.00 |
|
|
‐1% |
42% |
0.706 |
| Low |
63 (16,962) |
1.34 |
(1.18, 1.52) |
0.96 |
(0.78, 1.18) |
0.706 |
|
|
|
| 1.2.6 Newly included trials |
|
|
|
|
|
|
|
|
|
| Trials in previous review (reference) |
82 (23,311) |
1.36 |
(1.23, 1.51) |
1.00 |
|
|
‐4% |
42% |
0.563 |
| Trials in update |
13 (3141) |
1.26 |
(0.99, 1.61) |
0.93 |
(0.71, 1.21) |
0.563 |
|
|
|
| 1.2.7a Type of trial |
|
|
|
|
|
|
|
|
|
| Efficacy (reference) |
62 (16,765) |
1.26 |
(1.12, 1.41) |
1.00 |
|
|
‐11% |
44% |
0.135 |
| Effectiveness |
23 (7956) |
1.50 |
(1.22, 1.83) |
1.19 |
(0.95, 1.50) |
0.135 |
|
|
|
| 1.2.7b Explicit strategy for dissemination |
|
|
|
|
|
|
|
|
| No (reference) |
91 (23,236) |
1.36 |
(1.23, 1.50) |
1.00 |
|
|
‐2% |
43% |
0.429 |
| Yes |
4 (3216) |
1.16 |
(0.78, 1.72) |
0.85 |
(0.57, 1.28) |
0.429 |
|
|
|
| 1.2.7c Unit of randomisation |
|
|
|
|
|
|
|
|
|
| Individual (reference) |
84 (20,930) |
1.35 |
(1.22, 1.50) |
1.00 |
|
|
‐7% |
43% |
0.741 |
| Cluster: practitioner level |
4 (2416) |
1.23 |
(0.88, 1.73) |
0.91 |
(0.64, 1.30) |
0.597 |
|
|
|
| Cluster: service level |
7 (3106) |
1.51 |
(1.00, 2.29) |
1.12 |
(0.73, 1.71) |
0.598 |
|
|
|
| 1.2.8a Risk of bias: sequence generation |
|
|
|
|
|
2% |
40% |
0.108 |
| Low (reference) |
45 (11,211) |
1.27 |
(1.10, 1.45) |
1.00 |
|
|
|
|
|
| High |
3 (1544) |
2.21 |
(1.32, 3.71) |
1.75 |
(1.02, 2.98) |
0.041 |
|
|
|
| Unclear |
47 (13,697) |
1.38 |
(1.21, 1.57) |
1.09 |
(0.90, 1.32) |
0.379 |
|
|
|
| 1.2.8b Risk of bias: allocation concealment |
|
|
|
|
|
6% |
40% |
0.032 |
| Low (reference) |
20 (6551) |
1.26 |
(1.06, 1.49) |
1.00 |
|
|
|
|
|
| High |
12 (3489) |
2.01 |
(1.46, 2.75) |
1.60 |
(1.12, 2.29) |
0.011 |
|
|
|
| Unclear |
63 (16,412) |
1.31 |
(1.17, 1.48) |
1.04 |
(0.85, 1.29) |
0.678 |
|
|
|
| |
|
|
|
|
|
|
|
|
|
| 1.2.8c Risk of bias: attrition |
|
|
|
|
|
|
|
|
| Low (reference) |
42 (11,479) |
1.32 |
(1.14, 1.54) |
1.00 |
|
|
‐6% |
43% |
0.926 |
| High |
14 (4060) |
1.39 |
(1.09, 1.78) |
1.05 |
(0.79, 1.41) |
0.714 |
|
|
|
| Unclear |
39 (10,913) |
1.36 |
(1.18, 1.57) |
1.03 |
(0.84, 1.27) |
0.787 |
|
|
|
| 1.2.8d Risk of bias: selective reporting |
|
|
|
|
|
‐4% |
42% |
0.369 |
| Low (reference) |
50 (10,272) |
1.43 |
(1.24, 1.64) |
1.00 |
|
|
|
|
|
| High |
7 (3230) |
1.47 |
(1.09, 1.99) |
1.03 |
(0.74, 1.44) |
0.863 |
|
|
|
| Unclear |
38 (12,950) |
1.25 |
(1.09, 1.44) |
0.88 |
(0.72, 1.07) |
0.200 |
|
|
|
| 1.2.8e Risk of detection bias: outcome type (biochemically validated versus self‐report) |
|
|
|
| Low risk [biochemically validated] (reference) |
67 (17,890) |
1.38 |
(1.23, 1.55) |
|
|
|
‐1% |
40% |
0.406 |
| High risk [self‐report] |
23 (5988) |
1.37 |
(1.14, 1.64) |
0.99 |
(0.80, 1.23) |
0.928 |
|
|
|
| Unclear risk |
5 (2574) |
1.12 |
(0.84, 1.50)) |
0.81 |
(0.59, 1.11) |
0.185 |
|
|
|
| 1.2.8f Risk of bias: blinding participants/personnel |
|
|
|
|
|
|
| Low (reference) |
3 (175) |
1.94 |
(0.86, 4.39) |
1.00 |
|
|
2% |
43% |
0.214 |
| High |
66 (20,764) |
1.40 |
(1.25, 1.56) |
0.72 |
(0.32, 1.64) |
0.431 |
|
|
|
| Unclear |
26 (5513) |
1.18 |
(0.98, 1.43) |
0.61 |
(0.26, 1.41) |
0.244 |
|
|
|
| 1.2.8g Risk of bias: blinding outcome assessors |
|
|
|
|
|
‐1% |
41% |
0.111 |
| Low (reference) |
15 (4915) |
1.18 |
(0.98, 1.43) |
1.00 |
|
|
|
|
|
| High |
0 (0) |
‐ |
‐ |
‐ |
‐ |
‐ |
|
|
|
| Unclear |
80 (21,537) |
1.41 |
(1.26, 1.57) |
1.19 |
(0.96, 1.49) |
0.111 |
|
|
|
| 1.2.8h Risk of bias: baseline imbalance |
|
|
|
|
|
|
|
|
| Low (reference) |
52 (15,295) |
1.33 |
(1.18, 1.50) |
1.00 |
|
|
3% |
40% |
0.043 |
| High |
13 (4101) |
1.09 |
(0.86, 1.38) |
0.82 |
(0.63, 1.07) |
0.138 |
|
|
|
| Unclear |
30 (7056) |
1.61 |
(1.32, 1.95) |
1.21 |
(0.96, 1.52) |
0.101 |
|
|
|
| 1.2.8i Risk of bias: contamination |
|
|
|
|
|
|
|
|
| Low (reference) |
75 (19,003) |
1.36 |
(1.22, 1.52) |
1.00 |
|
|
‐4% |
43% |
0.723 |
| High |
14 (4266) |
1.24 |
(0.98, 1.58) |
0.91 |
(0.70, 1.19) |
0.490 |
|
|
|
| Unclear |
6 (3183) |
1.46 |
(0.99, 2.14) |
1.07 |
(0.71, 1.60) |
0.737 |
|
|
|
| 1.2.9 Program fidelity |
|
|
|
|
|
|
69% |
23% |
< 0.001 |
| High (good) fidelity (reference) |
27 (8154) |
1.26 |
(1.10, 1.44) |
1.00 |
|
|
|
|
|
| Low (poor) fidelity |
37 (12,770) |
1.12 |
(0.99, 1.26) |
0.89 |
(0.74, 1.07) |
0.206 |
|
|
|
| Unclear fidelity |
31 (5528) |
1.79 |
(1.52, 2.10) |
1.42 |
(1.15, 1.75) |
0.001 |
|
|
|
| |
|
|
|
|
|
|
|
|
|
