Table 1.
Sociodemographic characteristics of study participants included in the parent cohort ELEMENTa and those included in the current analysesb.
| Excluded from analysis (n = 693) Mean ± SD or % | Included in analysis (n = 133) Mean ± SD or % | |
|---|---|---|
| Child Sex (% female) | 48.8% | 51.9% |
| Estimated gestational age at birth (weeks) | 38.9 ± 1.5 | 38.9 ± 1.5 |
| Preterm birth (< 37 week gestation) | 6.2% | 5.3% |
| Birth weight (kg) | 3.10 ± 0.45 | 3.24 ± 0.44* |
| Low Birth weight (<2500 g) | 6.5% | 3.0% |
| Maternal age at delivery (years) | 28.9 ± 5.9 | 28.8 ± 5.6 |
| Maternal years of education at delivery | 9.0 ± 3.9 | 6.3 ± 4.6* |
| Family SES | ||
| Low | 54.2% | 47.4% |
| Medium | 43.2% | 36.9% |
| Higher | 2.6% | 3.4% |
| Maternal IQ (WAIS) | 88.6 ± 22.2 | 94.7 ± 20.1* |
| Maternal smoking during pregnancy (% yes) | 4.4% | 1.7% |
| Study cohort (years of subject birth) | ||
| 1 (1994–1995) | 29.1% | 1.5%* |
| 2 (1997–2002) | 35.3% | 13.5% |
| 3 (1998–2001) | 16.5% | 22.6% |
| 4 (2001–2006) | 19.2% | 62.4% |
| Age at BASC-2 administration (years) | 10.2 ± 2.7 | 8.4 ± 1.4* |
| BASC-2 percentiles | ||
| Behavioral Symptoms Index | 50.5 ± 9.5 | 50.1 ± 10.2 |
| Internalizing Problems | 52.1 ± 10.4 | 52.2 ± 10.0 |
| Anxiety | 53.3 ± 10.0 | 55.0 ± 10.2 |
| Depression | 51.7 ± 10.7 | 51.3 ± 11.2 |
| Externalizing Problems | 49.3 ± 9.5 | 48.1 ± 9.8 |
| Hyperactivity | 49.3 ± 9.8 | 49.6 ± 10.3 |
| Attention | 52.4 ± 10.8 | 52.6 ± 11.2 |
*
Indicates significant difference between groups, p < 0.05;
a
Not including those subjects included in current analyses.
b
Missing data for some covariates among subjects in current analyses; gestational age (n = 1), birth weight (n = 1), maternal age (n = 1), Family SES (n = 17), Maternal IQ (n = 19), maternal smoking (n = 18),