TABLE 2.
Birth Risk Factors and 16-Year Neurodevelopmental Status in Screen-Positives and Screen-Negatives According to Sample Retention From 16 to 21 Years
| Screened Positive at 16 y of Age |
Screened Negative at 16 y of Age |
|||
|---|---|---|---|---|
| Retained in Sample (n = 70) | Not Retained in Sample (n = 47) | Retained in Sample (n = 119) | Not Retained in Sample (n = 387) | |
| Perinatal risk factors | ||||
| HUS status | ||||
| NA, % (reference category) | 58.6 | 66.0 | 84.0 | 81.1 |
| Germinal matrix and/or intraventricular hemorrhage, % | 18.6 | 14.9 | 14.3 | 14.0 |
| Parenchymal lesion and/or ventricular enlargement, % | 22.9 | 19.1 | 1.7 | 4.9 |
| Birth social risk: ≥1 of 5 risk conditions, %a | 38.6 | 73.9 | 26.1 | 46.8 |
| Minority status, % | 18.6 | 53.2 | 11.8 | 30.0 |
| Less than high school education, %b | 11.9 | 26.2 | 6.5 | 12.0 |
| Age < 19 y, % | 2.9 | 10.9 | 1.7 | 6.7 |
| Unmarried, %c | 15.4 | 42.5 | 8.2 | 26.3 |
| Receiving public assistance, %d | 16.1 | 51.3 | 14.7 | 21.1 |
| Male gender, % | 54.3 | 59.6 | 56.3 | 45.0 |
| Birth weight, mean ± SD, g | 1420 ± 395 | 1404 ± 370 | 1507 ± 348 | 1484 ± 344 |
| ≥1500 g, % (reference category) | 50.0 | 44.7 | 55.5 | 53.0 |
| 1000–1499 g, % | 30.0 | 40.4 | 33.6 | 36.2 |
| <1000 g, % | 20.0 | 14.9 | 10.9 | 10.9 |
| Gestational age, mean ± SD, completed wk | 31 ± 3 | 31 ± 3 | 31 ± 3 | 31 ± 3 |
| >36 wk, % (reference category) | 5.7 | 0.0 | 1.7 | 4.4 |
| 34–36 wk, % | 20.0 | 17.0 | 21.0 | 18.9 |
| 28–31 wk, % | 48.6 | 38.3 | 42.0 | 41.3 |
| <28 wk, % | 15.7 | 14.9 | 16.0 | 10.9 |
| Small for gestational age, %e | 34.3 | 31.9 | 22.7 | 34.9 |
| Bronchopulmonary dysplasia (%)f | 11.6 | 6.4 | 5.0 | 4.2 |
| Neurodevelopment at age 16 y | ||||
| Disabled cognitively or motorically, %g | 18.6 | 23.4 | 0.8 | 1.3 |
| Inability to walk without assistance, %h | 12.9 | 12.8 | 0.8 | 1.3 |
| Severe intellectual impairment, %i | 14.3 | 23.4 | 0.0 | 0.8 |
Significant interaction between screen status and retention status. The only significant interaction involved a greater disparity between retained and not retained in the percentage of mothers who received public assistance at the time of their child's birth among the screen-positives than among the screen-negatives (Wald χ21 = 4.92, P = .027). In the screen-positives, the percentage of mothers receiving assistance in those retained was 35.2 percentage points lower than in those not retained (χ21 = 14.17, P < .001), whereas among the screen-negatives this percentage was 6.4 percentage points lower in those retained than in those not retained (χ21 = 1.86, P = .172).
Significant main effects for retention in sample, irrespective of screen status. Those not retained (n = 434) compared with those retained (n = 189) were more likely to be male and small for gestational age (55.6% vs 46.5%, and 34.6% vs 27.0%, respectively; both P < .05). They were also more likely to have ≥1 social risk factors (49.7% vs 30.7%; P < .001). Of the social risk factors, those not retained were more likely to be of minority status (32.5% vs 14.3%; P < .01) and to be unmarried (28.0% vs 11.0%; P < .001).
Significant main effects for screen status, irrespective of retention in sample. Those who screened positive at age 16 years (n = 117) compared with those who screened negative (n = 506) had slightly lower mean birth weights (1413.6 vs 1489.6 g; P < .05) and were more likely to have parenchymal lesions or ventricular enlargement as determined by neonatal head ultrasound (21.4% vs 4.2%; P < .001). At the time of the adolescents' birth, the mothers of those who screened positive were more likely than the mothers of those who screened negative to have ≥1 social risk factors (52.6% vs 41.9%; P < .001). They were more likely to be a member of a minority (32.5% vs 25.7%; P < .01), to have less than a high school education (17.4% vs 10.7%; P < .05), to be unmarried (25.7% vs 22.2%; P < .05), and to be receiving public assistance (29.7% vs 19.6%; P < .001). The adolescents were also more likely to be disabled (either cognitively or motorically) and more likely to be nonambulatory and severely mentally disabled (20.5% vs 1.2%, 12.8% vs 1.2%, and 18.8% vs 0.6%, respectively; all, P <0.001) at age 16 years. Males were only marginally more common among the screen-positives (56.4%) than among the screen-negatives (47.6%) (P < .10).
NA indicates not available.
Components are listed in the 5 succeeding rows. When ≥1 components of risk were missing, the total was pro-rated by multiplying 5 by the proportion of nonmissing risk factors that were positive for risk.
Not present for all cases; column n values are 67, 42, 107, and 343, respectively.
Not present for all cases; column n values are 65, 40, 93, and 335, respectively.
Not present for all cases; column n values are 62, 39, 95, and 313, respectively
In the lowest decile of the distribution of weight for gestational age using the gender-specific norms of Yudkin et al.48
Defined as the need for oxygen and/or ventilatory support at 36 weeks postmenstrual age. Not present for all cases; column n values are 69, 47, 119, and 385, respectively.
Severe intellectual impairment or inability to walk without assistance.
Item 5 of the Activities Limitations Questionnaire.49
For those seen in person at age 16 years, Wechsler Abbreviated Scale of Intelligence, Full-Scale IQ (FSIQ)50 <55 or untestable and ≥2 domains of the Vineland Adaptive Behavior Scale (VABS)51 scored as low or moderately low; for those assessed by telephone interview at that age, average of FSIQ scores from testing at 6 and/or 9 years <55 and ≥2 subdomains of the VABS scored as low or moderately low, or when FSIQ data were unavailable from earlier waves of testing, a composite score of the VABS from the telephone interview <55.