Table 2.
Sample descriptive statisticsa
| Outcome measures | Available case sample by variable | Complete case sample 1951 | Imputation sample 6351 |
|---|---|---|---|
| n (%) | % (SE for the percentage) | ||
| Harmful alcohol (Yes) | 3167 | 273 (18.9%) | 16% (0.6) |
| No | 1169 (81.1%) | 84% (0.6) | |
| Daily smoking (Yes) | 3195 | 121 (8.3%) | 14% (0.6) |
| No | 1330 (91.7%) | 86% (0.6) | |
| Nicotine dependence (Yes) | 3193 | 50 (3.5%) | 6% (0.4) |
| No | 1400 (96.6%) | 94% (0.4) | |
| Obesity (Yes) | 3202 | 183 (12.6%) | 11% (0.5) |
| No | 1270 (88%) | 89% (0.5) | |
| High waist circumference (Yes) | 3194 | 411 (28.3%) | 29% (0.7) |
| No | 1042 (71.7%) | 71% (0.7) | |
| High waist-hip ratio (Yes) | 3194 | 114 (7.9%) | 10% (0.4) |
| No | 1339 (92.2%) | 90% (0.4) | |
| Exposure measure | |||
| Cancer Risk Exposure AUC (0–21) | 1951 | ||
| Mean (SD) | 9.57 (4.21) | 9.72 (3.98) | |
| Median (IQR) | 8.75 (6.5–12) | 9.63 (6.6–12.1) | |
| Confounder measures | |||
| Sex | 6351 | ||
| Female | 1171 (60%) | 52% (0.6) | |
| Male | 780 (40%) | 48% (0.6) | |
| Maternal education | 5540 | ||
| Degree | 458 (24%) | 17% (0.5) | |
| A level | 562 (29%) | 28% (0.6 | |
| O level | 632 (33%) | 35% (0.6) | |
| < O level | 271 (14%) | 20% (0.5) | |
| Parental socioeconomic position | 5319 | ||
| Professional | 401 (21%) | 17% (0.5) | |
| Managerial and technical | 886 (47%) | 45% (0.7) | |
| Skilled non-man | 417 (22%) | 24% (0.6) | |
| Skilled man, part or unskilled | 169 (9%) | 14% (0.5) | |
| Housing tenure | 6169 | ||
| Mortgage/owned | 1704 (89%) | 84% (0.5) | |
| Private rent | 91 (5%) | 8% (0.4) | |
| Subsidised rent | 127 (7%) | 8% (0.3) | |
| Income | 5105 | ||
| High | 490 (27%) | 24% (0.6) | |
| Mid-high | 454 (25%) | 22% (0.6) | |
| Middle | 394 (22%) | 21% (0.6) | |
| Mid-low | 305 (17%) | 19% (0.6) | |
| Low | 183 (10%) | 15% (0.5) | |
| IQ: mean (SD) | 5433 | 109.8 (16.18) | 105.4 (17.53) |
| Maternal smoking | 5342 | 218 (12%) | 18% (0.5) |
| No | 1632 (88%) | 82% (0.5) | |
| Harmful maternal alcohol consumption | 5170 | 481 (27%) | 25% (0.6) |
| No | 1321 (73%) | 75% (0.6) | |
| Maternal cannabis use | 5377 | 58 (3%) | 4% (0.3) |
| No | 1798 (97%) | 96% (0.3) | |
| Maternal physical activity (hrs per week): mean (SD) | 5604 | 3.35 (5.38) | Mean = 3.96 (6.38) |
| Birthweight: mean (SD) | 5347 | 3437.5 (507.6) | Mean = 3440 (559.45) |
| Gestational age: mean (SD) | 5347 | 276.8 (11.9) | Mean = 276.2 (13.55) |
| Maternal unhealthy diet: mean (SD) | 5201 | 0.03 (0.79) | Mean = 0.08 (0.80) |
| Child depressive symptoms short moods and feelings questionnaire (SMFQ): mean (SD) | 5347 | 2.27 (2.93) | Mean = 2.47 (3.19) |
| Child antisocial behaviour: mean (SD) | 5276 | 0.26 (0.68) | Mean = 0.34 (0.80) |
| Child total difficulties score strengths and difficulties questionnaire (SDQ): mean (SD) | 5459 | 6.00 (4.42) | Mean = 6.58 (4.78) |
| Adverse childhood experiences (ACEs): mean (SD) | 3396 | 1.03 (1.21) | Mean = 1.31 (1.59) |
| Maternal Body mass index (BMI): mean (SD) | 5749 | 22.59 (3.52) | Mean = 22.88 (3.98) |
aTo calculate the number of cases missing in the imputation sample, subtract the available case sample by variable from 6351
SD standard deviation, IQR inter quartile range, SE standard error