Rates (%) of problem behaviour, cognitive impairment, school achievement and special education assistance in VLBW and CHDS cohorts after adjustment for covariates
| Measure | VLBW cohort | CHDS cohort | p Value | Significant covariatesa | |||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
| <1000 g | 1000g–1499 g | ||||||||||
| Behaviour problems: | |||||||||||
| Inattention/hyperactivity | 27.0 | 23.8 | 7.0 | <0.0001 | 1,2,6–8 | ||||||
| Conduct problems | 14.2 | 18.6 | 8.0 | <0.0001 | 1–3,5,7 | ||||||
| Anxiety/withdrawal | 29.8 | 20.0 | 6.9 | <0.0001 | 8,9 | ||||||
| Cognitive impairment: | |||||||||||
| WISC-R Total IQ <85 | 36.2 | 24.7 | 10.7 | <0.0001 | 2,5,6,8,9 | ||||||
| Below average school performance: | |||||||||||
| Reading | 31.0 | 31.8 | 15.2 | <0.0001 | 1–4,8,9 | ||||||
| Written expression | 40.7 | 36.5 | 20.4 | <0.0001 | 1–4,8 | ||||||
| Spelling | 45.9 | 40.8 | 21.1 | <0.0001 | 3,4,6,8 | ||||||
| Mathematics | 43.7 | 37.5 | 15.7 | <0.0001 | 1,2,8 | ||||||
| Physical education | 32.8 | 22.3 | 9.4 | <0.0001 | 1,5,8 | ||||||
| Special education assistance: | |||||||||||
| Enrolled in special school, class or unit | 8.7 | 6.5 | 1.1 | <0.0001 | 5,9 | ||||||
| Receiving any form of special education assistance | 30.7 | 24.1 | 9.3 | <0.0001 | 1,2 | ||||||
3-150 Significant covariates: 1 = gender; 2 = maternal education; 3 = maternal age; 4 = maternal parity; 5 = single parent family; 6 = duration of breastfeeding; 7 = maternal smoking during pregnancy; 8 = grade level; 9 = age at assessment.