Table 2.

Effect of Birth Weight and Gestational Age on CBCL Total Problems. Shown are Beta Estimates [and 95% Confidence Intervals], t-statistics and p-values from Wald Tests

	M1	M2	M3
N	9,076	8,208	8,142
	Adjusted for sex	M1 + Adjusted for socioeconomic factors & race/ethnicity	M2 + Adjusted for family history of mental illness
Birth weight	-0.43 [-0.74, -0.12]**	-0.69 [-1.04, -0.34]***	-0.36 [-0.65, -0.06]*
	t = -2.70, p = 0.007	t = -3.90, p < 0.001	t = -2.35, p = 0.02
Birth weight (controlling for gestational age group)	0.02 [-0.32, 0.36]	-0.11 [-0.49, 0.26]	-0.12 [-0.44, 0.21]
	t = 0.12, p = 0.91	t = -0.58, p = 0.56	t = -0.71, p = 0.48
Gestational age groupa (controlling for birth weight)
Early-term (37–38 wks)	6.23 [4.84, 7.63]***	4.82 [3.44, 6.20]***	3.34 [2.10, 4.57]***
	t = 8.76, p < 0.001	t = 6.88, p < 0.001	t = 5.30, p < 0.001
Late preterm (34–36 wks)	3.66 [2.50, 4.81]***	3.73 [2.47, 4.98]***	1.83 [0.85, 2.82]***
	t = 6.22, p < 0.001	t = 5.83, p < 0.001	t = 3.64, p < 0.001
Early-moderate preterm (≤ 33 wks)	1.11 [-0.54, 2.76]	2.21 [0.22, 4.19]*	0.43 [-1.21, 2.06]
	t = 1.32, p = 0.19	t = 2.18, p = 0.03	t = 0.51, p = 0.61

Beta estimates are in original units of the CBCL. M1-M3 refer to models with increasing numbers of covariates

^*p < .05; **p < .01; ***p < .001

^aReference group: Full-term (39 + weeks gestation)