Table 2.

The result of subgroup analysis on the breastfeeding self-efficacy.

Subgroups	SMD (95% CI)	No. of study	I 2
Primiparous	1.21 (0.57–1.86)	24	98.5
Multiparous	1.09 (0.45–1.74)	16	97.6
Group	1.48 (0.61–2.35)	15	98.8
Individual	0.99 (0.46–1.52)	25	97.7
Phone	0.80 (0.04–1.56)	21	98.3
Direct education	1.57 (1.0–2.14)	19	98.1
Theory	2.56 (1.80–3.32)	11	96.9
No theory	0.64 (0.11–1.17)	29	98.3
Postpartum	0.08 (−0.48–0.65)	11	96.2
Pregnancy	1.67 (1.08–2.26)	29	98.5
Hospital	0.36 (−0.15–0.87)	21	98.0
Health center	2.31 (1.46–3.17)	19	98.2
Asia	1.70 (1.21–2.20)	23	97.1
Others	0.46 (−0.30–1.22)	17	98.6
Higher-quality studies	0.10 (−0.61–0.81)	9	95.6
Lower-quality studies	1.52 (1.01–2.04)	31	98.0
At discharge up to 1 week	1.49 (1.36–1.61)	9	96.9
2 weeks	1.18 (1.01–1.35)	7	85.6
4 weeks	0.64 (0.54–0.73)	13	86.5
6 weeks	0.61 (0.50–0.73)	4	77.4
8 weeks	0.53 (0.42–0.63)	16	97.8
12 weeks	−0.35 (−0.50–0.21)	8	99.2
16 weeks	0.87 (0.62–1.13)	4	98.8
24 weeks	0.93 (0.72–1.14)	4	98.9