Plasma Levels of Polychlorinated Biphenyls, Non-Hodgkin Lymphoma, and Causation

Table 4

List of contributing strata and OR metrics satisfying the meta-analysis criteria. Results of the Chi-square test for homogeneity (𝑃 values and degrees of freedom, DOF) are shown for each meta-analyzed congener. Note that congener 118 is statistically heterogeneous (𝑃<0.025). However, removal of the weighted outlier [46] indicated homogeneity in the remaining strata. A combined test of all congeners indicated overall homogeneity (𝑃>0.10 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	𝑃>0.10 (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	𝑃>0.10 (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	𝑃<0.025 (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	𝑃>0.10 (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	𝑃>0.10 (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	𝑃>0.10 (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	𝑃>0.10 (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	𝑃>0.10 (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	𝑃>0.10 (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	𝑃>0.10 (1)
De Roos et al., 2005 [26]	Quartile	187	1.22	0.49	3.08