Table 1.
Descriptive statistics for covariates; injuries from birth to age 16 years
| No injury | TBI | OI | p value* | |
|---|---|---|---|---|
| (n = 8307) | (n = 800) | (n = 2305) | ||
| N (%) | N (%) | N (%) | ||
| Male | 4109 (49.5) | 457 (57.1) | 1283 (55.7) | <0.001 |
| Social class IV–Va | 3052 (42.9) | 273 (37.7) | 786 (39.5) | 0.001 |
| Rented subsidised housing | 967 (12.5) | 60 (8.0) | 181 (8.5) | <0.001 |
| Mother completed secondary school | 4826 (63.4) | 434 (57.7) | 1236 (58.9) | <0.001 |
| Maternal daily smoking | 2246 (28.6) | 212 (27.6) | 576 (26.7) | 0.186 |
| Maternal daily alcohol use | 989 (12.6) | 110 (14.3) | 309 (14.3) | 0.067 |
| Three or more early life eventsb | 4107 (52.9) | 470 (61.6) | 1220 (57.1) | <0.001 |
| M (SD) | M (SD) | M (SD) | ||
|---|---|---|---|---|
| Maternal age at birth (years) | 28.42 (4.76) | 28.92 (4.76) | 28.72 (4.74) | 0.001 |
| Bonding at 8 monthsc | 28.25 (3.68) | 28.08 (3.55) | 28.20 (3.59) | 0.512 |
| Positive parenting experience at 21 monthsd | 5.99 (1.51) | 6.01 (1.53) | 6.00 (1.55) | 0.934 |
| Negative parenting experience at 21 monthsd | 20.80 (2.74) | 20.63 (2.84) | 20.77 (2.73) | 0.281 |
TBI traumatic brain injury, OI orthopaedic injury
* p values calculated using Chi square or analysis of variance
aHighest social class of either parent is skilled non-manual or lower occupation based on the Registrar General’s classification of occupations
bParent-reported questionnaire relating to upsetting events in the child’s life completed when offspring was 6, 30, 42 and 81 months old
cParent-report questionnaire completed when offspring was 8 months old
dPositive and negative parenting experiences based on parent-completed questionnaire when offspring was 21 months old