Table 2

Maternal risk of preterm delivery: overall and by county of residence aggregated by quintile of composite Gallup-Sharecare Well-Being Index (WBI) score, unadjusted and adjusted for maternal risk factors

Variable	Coefficient (95% CI)	P value	Wald p	Coefficient (SE)	P value	Wald p
Intercept	0.131	<0.001		0.120 (0.118,0.123)	<0.001
Intercept	(0.128 to 0.134)	<0.001		0.120 (0.118,0.123)	<0.001
WBI score			<0.001			<0.001
Q1	ref			ref
Q2	–	0.001		−0.006 (−0.009,–0.003)	<0.001
Q3	−0.006 (−0.010 to 0.002)	<0.001		−0.013 (-0.016,–0.010)	<0.001
Q4	−0.013 (−0.017 to 0.009)	<0.001		−0.014 (-0.017,–0.012)	<0.001
Q5	−0.015 (−0.019 to 0.012)	<0.001		−0.019 (-0.022,–0.016)	<0.001
	−0.022 (−0.026 to 0.018)
Maternal age
≤19				ref
20–24				−0.019 (-0.020,–0.017)	<0.001
25–29				−0.021 (-0.022,–0.020)	<0.001
30–34				−0.016 (-0.017,–0.014)	<0.001
35–39				0.002 (0.000,0.003)	0.018
≥40				0.023 (0.021,0.025)	<0.001
Maternal race
White				ref
Black				0.051 (0.050,0.052)	<0.001
American Indian/Native American				0.024 (0.021,0.027)	<0.001
Asian				0.011 (0.009,0.012)	<0.001
Mother is Hispanic
No				ref
Yes				0.015 (0.014,0.015)	<0.001
Maternal smoking
No				ref
Yes				0.030 (0.029,0.031)	<0.001
Unknown				0.004 (0.002,0.007)
Payer
Medicaid				ref
Private				−0.019 (0.000)	<0.001
Self				−0.012 (0.001)	<0.001
Other				−0.013 (0.001)	<0.001
Unknown				−0.005 (0.001)	<0.001
Timing of first prenatal visit
1st–3rd month				ref
4th–6th month					<0.001
7th month–term				−0.019 (-0.020,–0.018)	<0.001
No prenatal visit				−0.012 (-0.014,–0.011)	<0.001
Unknown				−0.013 (-0.014,–0.011)	<0.001
				−0.005 (-0.008,–0.002)
				−0.004 (-0.006,–0.003)
Infant sex					–
Female				ref
Male				0.011 (0.010,0.011)	<0.001
Multiple births
No				ref
Yes				0.487 (0.485,0.489)	<0.001
R²	0.078			0.656

GHWBI, Gallup-Sharecare Well-Being Index.