TABLE 2—

Estimated Cotinine Ratios by Child Characteristics, Black and White Children With Lead Levels of ≤ 9 μg/dL: United States, 2011–2012

Variable	Cotinine Ratio (95% CI)
Black race	3.06 (1.91, 4.89)
Age: 6-mo increase	1.16 (1.07, 1.26)
Female gender	1.03 (0.85, 1.24)
Summer month of collection	1.05 (0.83, 1.32)
Medicaid recipient	3.38 (2.50, 4.55)
State smoking rate: 1% increase	1.56 (1.34, 1.82)
State average winter temperature: 1°F increase	1.18 (1.09, 1.26)
Black race × age interaction	0.88 (0.79, 0.98)
Black race × Medicaid interaction	0.39 (0.27, 0.58)
Smoking rate × winter temperature interaction	0.99 (0.99, 1.00)

Note. CI = confidence interval. Data were derived from a multivariate analysis with left censored data. Dried blood spots for which any of the corresponding child characteristics were missing were excluded from this analysis (n = 81). The sample size was n = 1460.