Distributions of outcome measures and sample size at each age
| Birth/infancy | 7 years | 9 years | 11 years | 15 years | Total N (at least one measure)* | |
|---|---|---|---|---|---|---|
| Health indicators | ||||||
| Global parent-assessed health, n (%) | N=9895 | N=7576 | N=7493 | N=6596 | 10663 | |
| 1 (very healthy, no problems) | 4817 (48.7) | 4652 (61.4) | 4902 (65.4) | 4237 (64.2) | ||
| 2 (healthy, few minor problems) | 4685 (47.4) | 2786 (36.8) | 2476 (33.0) | 2263 (34.3) | ||
| 3 or 4 (sometimes quite ill, or almost always unwell) | 393 (4.0) | 138 (1.8) | 115 (1.5) | 96 (1.5) | ||
| Mean (SD) | 1.55 (0.57) | 1.40 (0.53) | 1.36 (0.51) | 1.37 (0.51) | ||
| Height (cm), mean (SD) | N=9655, 50.63 (2.49) | N=7474, 125.61 (5.39) | N=6971, 139.51 (6.28) | N=6510, 150.76 (7.25) | N=4810, 169.26 (8.37) | 11463 |
| DXA-assessed fat-mass (kg), median (IQR) | N=6702, 7.18 (4.79, 10.94) | N=6411, 9.78 (6.63, 15.26) | N=4766, 13.62 (8.28, 19.93) | 7642 | ||
| Cholesterol (mmol/l), mean (SD) | N=4674, 4.27 (0.66) | N=3203, 3.75 (0.64) | 5560 | |||
| HDL cholesterol (mmol/l), mean (SD) | N=4674, 1.40 (0.31) | N=3203, 1.28 (0.29) | 5560 | |||
| Triglycerides (mmol/l), median (IQR) | N=4674, 1.00 (0.76, 1.38) | N=3203, 0.75 (0.60, 0.98) | 5560 | |||
| C reactive protein (mg/l), median (IQR) | N=4674, 0.21 (0.11, 0.54) | N=3203, 0.39 (0.22, 0.89) | 5560 | |||
| SBP (mm Hg), mean (SD) | N=7346, 98.86 (9.18) | N=6292, 102.83 (7.71) | N=6446, 105.49 (9.86) | N=4704, 123.12 (10.78) | 8488 | |
| DBP (mm Hg), mean (SD) | N=7344, 56.46 (6.63) | N=6292, 60.00 (6.88) | N=6446, 58.72 (6.53) | N=4704, 67.59 (8.75) | 8487 | |
| BMD (g/cm2), mean (SD) | N=6702, 0.90 (0.05) | N=6411, 0.95 (0.06) | N=4766, 1.11 (0.08) | 7642 | ||
| Behavioural outcomes | ||||||
| Total difficulties score (range 0–40), mean (SD) | N=7119, 7.09 (4.21) | N=6353, 6.24 (4.20) | N=5819, 5.92 (4.19) | 8708 | ||
| Hyperactivity score (range 0–10), mean (SD) | N=7119, 3.28 (2.30) | N=6353, 2.79 (2.17) | N=5819, 2.60 (2.13) | 8708 | ||
| Emotional problems score (range 0–10), mean (SD) | N=7119, 1.42 (1.56) | N=6353, 1.39 (1.60) | N=5819, 1.33 (1.56) | 8708 | ||
| Conduct difficulties score (range 0–10), mean (SD) | N=7119, 1.52 (1.35) | N=6353, 1.16 (1.26) | N=5819, 1.08 (1.26) | 8708 | ||
| Peer problems score (range 0–10), mean (SD) | N=7119, 0.97 (1.28) | N=6353, 1.00 (1.32) | N=5819, 0.96 (1.34) | 8708 | ||
| Educational outcomes | ||||||
| Summary educational attainment measure (%), mean (SD) | N=10365, 66.16 (15.54) | N=8856, 52.24 (11.20) | 10659 | |||
| English test scores (%), mean (SD) | N=10506, 58.63 (15.74) | N=9022, 46.27 (17.26) | 10735 | |||
| Mathematics test scores (%), mean (SD) | N=10582, 64.94 (21.19) | N=9276, 54.80 (14.62) | 10812 | |||
| Science test scores (%), mean (SD) | N=10633, 73.95 (15.20) | N=9330, 54.29 (13.53) | 10840 | |||
*The total sample size for each outcome is the number of individuals with one or more measure at any age. The statistical analysis technique uses all available measures for each individual, as well as the observed changes with age across the whole dataset, to estimate a full trajectory across all ages for that individual.
BMD, bone mineral density; DBP, diastolic blood pressure; DXA, dual x-ray accelerometry; HDL, high-density lipoprotein; SBP, systolic blood pressure.