Table 4: List of contributing strata and OR metrics satisfying the meta-analysis criteria. Results of the Chi-square test for homogeneity ( values and degrees of freedom, DOF) are shown for each meta-analyzed congener. Note that congener 118 is statistically heterogeneous (). However, removal of the weighted outlier [46] indicated homogeneity in the remaining strata. A combined test of all congeners indicated overall homogeneity ( and 37 DOF).

Study (strata) Percentile type PCB congener OR LCL UCL Homogeneity test (Chi-Square DOF) Spinelli et al., 2007 [42] Tertile 28 0.95 0.67 1.34 (1) Cocco et al., 2008 [46] Quartile 28 1.60 0.80 3.20 Spinelli et al., 2007 [42] Quartile 99 1.27 0.86 1.87 (1) De Roos et al., 2005 [26] Quartile 99 0.77 0.28 2.10 Engel et al., 2007-J [41] Quartile 118 1.70 0.90 3.50 (6) Engel et al., 2007-C [41] Quartile 118 5.40 1.70 17.10 Spinelli et al., 2007 [42] Quartile 118 1.77 1.15 2.72 De Roos et al., 2005 [26] Quartile 118 0.73 0.29 1.84 Cocco et al., 2008 [46] Quartile 118 0.40 0.20 0.80 Laden et al., 2010 [48] Quartile 118 0.81 0.42 1.56 Bertrand et al., 2010 [47] Quintile 118 1.40 0.76 2.50 Engel et al., 2007-J [41] Quartile 138 1.70 0.80 3.20 (5) Engel et al., 2007-C [41] Quartile 138 4.40 1.50 12.60 Spinelli et al., 2007 [42] Quartile 138 1.46 0.98 2.18 Cocco et al., 2008 [46] Quartile 138 1.10 0.60 2.00 Laden et al., 2010 [48] Quartile 138 0.95 0.49 1.83 Bertrand et al., 2010 [47] Quintile 138 1.80 0.98 3.20 Engel et al., 2007-J [41] Quartile 153 2.00 1.00 3.90 (6) Engel et al., 2007-C [41] Quartile 153 2.20 0.90 5.20 Spinelli et al., 2007 [42] Quartile 153 1.79 1.17 2.72 De Roos et al., 2005 [26] Quartile 153 1.59 0.63 4.00 Cocco et al., 2008 [46] Quartile 153 1.00 0.70 2.50 Laden et al., 2010 [48] Quartile 153 0.82 0.43 1.56 Bertrand et al., 2010 [47] Quintile 153 2.10 1.10 3.80 Spinelli et al., 2007 [42] Quartile 156 1.77 1.14 2.74 (1) De Roos et al., 2005 [26] Quartile 156 2.70 0.97 7.50 Spinelli et al., 2007 [42] Quartile 170 1.80 1.16 2.79 (2) De Roos et al., 2005 [26] Quartile 170 1.73 0.73 4.14 Cocco et al., 2008 [46] Quartile 170 1.00 0.50 1.80 Spinelli et al., 2007 [42] Quartile 180 1.91 1.19 3.07 (4) De Roos et al., 2005 [26] Quartile 180 3.50 1.34 9.15 Laden et al., 2010 [48] Quartile 180 1.03 0.52 2.02 Cocco et al., 2008 [46] Quartile 180 1.50 0.70 3.20 Bertrand et al., 2010 [47] Quintile 180 2.40 1.30 4.50 Spinelli et al., 2007 [42] Tertile 183 1.22 0.87 1.71 (1) De Roos et al., 2005 [26] Quartile 183 1.02 0.36 2.93 Spinelli et al., 2007 [42] Quartile 187 1.92 1.23 2.98 (1) De Roos et al., 2005 [26] Quartile 187 1.22 0.49 3.08