TABLE 1.
Summary statistics of continuous covariates in the Detroit Longitudinal Cohort study (N=232)
| Mean | SD | |
|---|---|---|
| Gestational age at recruitment (weeks) | 23.8 | 7.5 |
| Number of prenatal visits | 5.8 | 3.0 |
| Smoking during pregnancy (cigarettes/day) | 9.5 | 11.2 |
| Prenatal marijuana exposure (days/month) | 0.9 | 2.9 |
| Prenatal cocaine exposure (days/month) | 1.0 | 2.9 |
| Prenatal opiate exposure (days/month) | 0.2 | 1.0 |
| Biological mother’s education (years) | 11.8 | 1.6 |
| Biological mother’s verbal IQ (PPVT score) | 71.7 | 11.7 |
| Beck Depression Inventory at 6-month postpartum follow-up | 11.2 | 7.5 |
| Age of a child at 7-year follow-up visit (years) | 7.9 | 0.3 |
| Socioeconomic status at age 7-year follow-upa | 26.2 | 10.4 |
| Primary caregiver’s verbal IQ (PPVT score)at 7-year follow-up | 72.9 | 12.5 |
| HOME score at 7-year follow-up | 33.7 | 6.9 |
| Beck Depression Inventory at 7-year follow-up | 8.3 | 7.4 |
| Number of stressful events at 7-year follow-upb | 10.2 | 5.5 |
| Perceived life stress at 7-year follow-upb | 36.7 | 27.8 |
a
Hollingshead Four Factor Index of Social Status (Hollingshead, 2011)
b
Life Events Scale (Holmes and Rahe, 1967)