. 2015 Feb 7;8(4):351–366. doi: 10.22074/ijfs.2015.4174

Table 4.

Summary of estimates of risk and heterogeneity in overall and sub-group analysis


Subgroup	Numbers ofstudies	Summary ORor RR (95% CI)	Measure of heterogeneity			Analysis
Subgroup	Numbers ofstudies	Summary ORor RR (95% CI)	Q-value	P value	I²	Model

Study design
Cohort studies	9	1.23 (0.91, 1.67)	69.63	0.0001	0.89	RE
Case control studies^A	4	1.30 (1.09, 1.56)	9.56	0.02	0.69	RE
Cohort studies
Air dioxin-related toxicantsexposure and adversepregnancy outcome	4	0.99 (0.85, 1.16)	4.17	0.24	0.28	FE
Food dioxin-related toxicantsexposure and
Spontaneous abortion	2	1.05 (0.80, 1.37)	1.30	0.25	0.23	RE
Low birth weight	2	1.55 (1.24, 1.94)	0.41	0.52	0	RE
Case control studies
Maternal solid contaminantsdioxin exposure and birth defects	3	1.24 (1.19, 1.29)	1.52	0.47	0	FE

RE; Random-effect model, FE; Fixed-effect model, I²; Index of inconsistency and A; Cannot extract effective data from two studies [Dimich-Ward et al. (32), Eskenazi et al. (17)].