Predictors of serum concentrations of polybrominated flame retardants among healthy pregnant women in an urban environment: a cross-sectional study

Table 4 Ratio of geometric means derived from regression models for specific PBDE congeners measured in maternal blood collected upon delivery

	PBDE 47	PBDE 99	PBDE 100	PBDE 153
# < LOD / Total observations^a	3 / 311	50 / 313	28 / 316	5 / 304
Model distribution	General Gamma	Log logistic	Log logistic	General Gamma
	Ratio of geometric means (95% CI)	Ratio of geometric means (95% CI)	Ratio of geometric means (95% CI)	Ratio of geometric means (95% CI)
Race/ethnicity
Non Hispanic White	1
African-American	1.47 (0.95, 2.29)^b
Hispanic	1.21 (0.92, 1.57)
Maternal education
Less than high school	1	1		1
High school or equivalent	1.76 (1.30, 2.37)*	1.39 (0.98, 1.97)^b		1.21 (0.92, 1.60)
College	1.59 (1.20, 2.10)*	1.27 (0.93, 1.73)		1.42 (1.10, 1.83)**
Graduate	1.45 (0.99, 2.12)^b	1.00 (0.69, 1.45)		0.95 (0.67, 1.34)
Household income
< $25,000				1
$25,000 – 50,000				1.22 (0.93, 1.62)
>$50,000				1.47 (1.15, 1.87)**
Pre-pregnancy BMI
Normal				1
Underweight				0.81 (0.57, 1.16)
Overweight				0.99 (0.81, 1.21)
Obese				0.65 (0.50, 0.85)**
Solid Dairy (reference:)
< 5 servings per week				1
5-10 servings per week				1.19 (0.97, 1.47)
>10 servings per week				1.25 (1.01, 1.56)*
Processed Meat
≤1 serving per week			1	1
Not reported			1.06 (0.79, 1.40)	1.14 (0.91, 1.44)
>1 servings per week			1.39 (1.10,1.76)**	1.53 (1.26, 1.86)**
Household electronics
< 10 electronics	1	1	1	1
≥ 10 electronics	1.70 (1.35, 2.13)**	1.41 (1.12, 1.77)**	1.37 (1.08, 1.74)**	1.32 (1.07, 1.63)**
Generalized R² ^c	12.2%	4.6%	5.7%	24.5%

^aSample size for each congener changes due to missing covariates.
^b0.05 < p < 0.09, *p < 0.05, ** p < 0.01.
^cGeneralized R2 indicates the proportion of variability in the data that is accounted for by the statistical model with multiple predictors.

ISSN: 1476-069X