TABLE 2

Means, SDs, Ranges, and Missing Data for Quantitative Predictor, Control, and Outcome Variables Before Data Imputation (N = 5107)

VariableMean (SD)RangeMissing Data N (%)
Child’s birth wt, g3410.15 (568.83)382.00–5440.0035 (0.7)
Child’s age wave 1, y0.77 (0.21)0.33–1.590 (0)
Child’s age wave 3, y4.88 (0.25)4.16–5.84721 (14)
Child’s age wave 4, y6.91 (0.29)6.16–7.92865 (17)
Child’s age wave 5, y8.99 (0.32)8.08–9.841022 (20)
Child’s age wave 6, y11.01 (0.33)10.08–11.841343 (26)
Mother’s age wave 1, y31.48 (5.47)15.66–63.927 (0.1)
Average daily cigarettes while pregnant1.19 (3.81)0.00–55.001041 (20)
Mother’s average daily cigarettes wave 12.09 (5.25)0.00–40.0823 (16)
WAI score wave 326.94 (7.10)1.00–43.00910 (18)
Adapted PPVT-III score wave 365.16 (5.99)34.00–85.00841 (17)
Adapted PPVT-III score wave 474.43 (5.15)36.00–92.00922 (18)
Adapted PPVT-III score wave 579.10 (4.83)52.00–106.001093 (21)
MR score wave 414.00 (4.67)3.00–30.00927 (18)
MR score wave 519.55 (4.83)1.00–32.001107 (22)
MR score wave 622.08 (5.07)1.00–33.001509 (30)
Breastfeeding duration, d228.89 (202.88)0.00–1157583 (11)