Table 1.

Comparisons of preintervention sample characteristics for the RCT population and selected and participating evaluation subsamples

Variable	RCT population versus selected and interviewed evaluation subsamples
	RCT population (n = 4,777)	Selected evaluation subsample (n = 664)	Participating evaluation subsample (n = 531)
% Participation of selected			80.0
Infant cumulative birth risk
% Low birth weight	10.0	9.1 (p = .50)	8.9 (p = .45)
% Gestation <37 weeks	8.2	6.7 (p = .17)	6.3 (p = .12)
% Any birth complications	7.4	5.8 (p = .13)	6.1 (p = .26)
% Cesarean section birth	30.6	31.6 (p = .59)	31.8 (p = .56)
% Medicaid/no insurance	60.8	63.1 (p = .26)	65.5 (p = .04)
Mother age (mean, years)	28.5	28.5 (p = .84)	28.3 (p = .58)
Mother race/ethnicity
%White, non-Hispanic	29.7	29.2 (p = .80)	26.6 (p = .13)
% Black	36.7	38.0 (p = .54)	39.4 (p = .23)
% Hispanic	22.6	23.2 (p = .71)	24.7 (p = .27)
% Other	11.1	9.6 (p = .27)	9.4 (p = .25)
% Infant female	49.8	54.7 (p < .01)	53.5 (p = .11)

Note: Column 2 and Column 3 are contrasted with Column 1, with significance level in parentheses. A Holm–Bonferroni sequential correction was applied to account for multiple tests of between-group differences. No moderation terms remained statistically significant after applying a Holm-Bonferroni sequential correction.