Table 2.

Subgroup analyses

Variables		No. of studies	HbA1c, SMD (95% CI)	p-value	Heterogeneity		Begg test	Egger test
					I2 (%)	p-value	p-value	p-value
All studies		12	-0.41 (-0.69, -0.13)	0.004	88	<0.001	0.410	0.519
Sample size
	<100	8	-0.45 (-0.79, -0.11)	0.009	84	<0.001	0.620	0.413
	≥100	4	-0.33 (-0.87, 0.20)	0.220	94	<0.001	0.496	0.988
Duration of intervention (mo)
	≤6	6	-0.52 (-0.96, -0.07)	0.020	89	<0.001	0.188	0.108
	>6	6	-0.32 (-0.71, 0.08)	0.120	90	<0.001	0.573	0.358
Baseline HbA1c (%)
	<8.5	9	-0.42 (-0.77, -0.07)	0.020	91	<0.001	0.404	0.540
	≥8.5	3	-0.36 (-0.62, -0.10)	0.006	11	0.320	0.601	0.692
Type of intervention delivery
	Individual	0	-	-	-	-	-	-
	Group	6	-0.28 (-0.51, -0.06)	0.010	70	0.005	0.188	0.072
	Combined	6	-0.53 (-1.07, 0.02)	0.060	92	<0.001	0.851	0.780
Frequency of contact
	Low	2	-0.53 (-1.60, 0.54)	0.330	98	<0.001	0.317	<0.001
	Moderate	3	-0.65 (-1.71, 0.40)	0.220	95	<0.001	0.601	0.494
	High	7	-0.29 (-0.48, -0.10)	0.003	52	0.050	0.652	0.933

SMD, standard mean difference; HbA1c, glycated hemoglobin A1c; CI, confidence interval.