Characteristics of the SPEEDY sample at waves 1–3
| Baseline | 1-Year follow-up† | 4-Year follow-up | ≥2 Time points‡ | |
|---|---|---|---|---|
| N consented | 2064 | 1019 | 480 | |
| N with ≥1 day PA data (% of consenting sample) | 1978 (95.8) | 930 (91.2) | 428 (89.2) | 990 (48.0% of baseline) |
| N with ≥3 days PA data (% of consenting sample) | 1868 (90.5) | 882 (86.6) | 386 (80.4) | 931 (45.1% of baseline) |
| Age (years) | 10.3 (0.3) | 11.2 (0.3) | 14.3 (0.3) | 10.2 (0.3)2 |
| Percentage of female | 55.6 | 58.42 | 53.5ns | 57.52 |
| Weight (kg) | 36.5 (8.4) | 57.1 (12.4) | 36.1 (8.4)ns | |
| Height (cm) | 141.0 (6.7) | 165.0 (7.6) | 141.0 (6.7)ns | |
| BMI z-score | 0.3 (1.1) | 0.4 (1.2) | 0.2 (1.1)2 | |
| Overweight and obese (%) | 23.0 | 20.6 | 22.03 | |
| Body fat percentage | 23.6 (6.7) | 21.5 (8.1) | 23.3 (6.6)2 | |
| Parental age at leaving education (≤16 vs >16 years) | 55.1 | 57.8ns | 56.22 | 57.5ns |
| Home location (all baseline values; %) | ||||
| Urban | 39.0 | 33.61 | 38.2ns | 35.11 |
| Town/suburban | 28.7 | 30.9 | 26.0 | 30.2 |
| Rural | 32.3 | 35.5 | 35.8 | 34.7 |
| Sedentary (min) | 455.3 (55.9) | 469.8 (54.8) | 500.7 (58.6) | 456.8 (53.7)ns |
| LPA (min) | 181.2 (32.7) | 177.1 (31.3) | 139.6 (33.5) | 181.9 (32.50)ns |
| MPA (min) | 48.7 (14.5) | 47.5 (13.9) | 42.9 (15.9) | 48.7 (13.9)ns |
| VPA (min) | 6.1 (6.5) | 6.1 (5.1) | 3.0 (4.2) | 6.1 (6.6)ns |
| MVPA (min) | 73.9 (25.2) | 71.7 (22.9) | 62.0 (24.7) | 73.8 (24.1)ns |
Participant characteristics are presented for participants with ≥1 day of physical activity data (mean and SD, unless otherwise stated).
t Tests or χ2 tests used to test differences between 1-year and 4-year follow-up and ≥2 waves compared to baseline data where appropriate: 1p<0.001; 2p<0.05; nsp>0.05.
Descriptive data presented for participants with ≥1 day accelerometer data at each wave.
Baseline values presented for participants who had data for ≥2 waves.
Wave 2 was postal data collection and anthropometry was not measured.
†Anthropometry data was not collected at 1-year follow-up.
‡Baseline data presented.
BMI, body mass index; LPA, light physical activity; MPA, moderate physical activity; MVPA, moderate and vigorous physical activity; PA, physical activity; SPEEDY, Sport, Physical activity and Eating behaviour: Environmental Determinants in Young people; VPA, vigorous physical activity.