Table 1.
Descriptive characteristics of the study population
| Data level | Characteristic | Total (n = 342) |
South Asian (n = 202) |
White British (n = 140) |
p-value ethnic difference |
|---|---|---|---|---|---|
| Participant | Sex (n (%)) | ||||
| Boys | 175 (51.2) | 100 (49.5) | 75 (53.6) | ||
| Girls | 167 (48.8) | 102 (50.5) | 65 (46.4) | 0.46 | |
| Area deprivationa (n (%)) | |||||
| Most deprived 10% | 209 (61.1) | 146 (72.3) | 63 (45.0) | ||
| > 10 to 30% | 94 (27.5) | 46 (22.8) | 48 (34.3) | ||
| > 30% | 39 (11.4) | 10 (4.9) | 29 (20.7) | < 0.001 | |
| Annual income (n (%)) | |||||
| <£6999 | 36 (27.1) | 19 (22.9) | 17 (34.0) | ||
| £7000 to £16,999 | 60 (45.1) | 46 (55.4) | 14 (28.0) | ||
| ≥£17,000 | 37 (27.8) | 18 (21.7) | 19 (38.0) | 0.008 | |
| Maternal delivery age (n (%)) | |||||
| < 25y | 74 (29.7) | 26 (20.2) | 48 (40.0) | ||
| ≥25 to < 30 | 98 (39.4) | 60 (46.5) | 38 (31.7) | ||
| ≥30y | 77 (30.9) | 43 (33.3) | 34 (28.3) | 0.002 | |
| Birth weight (n (%)) | |||||
| Low | 10 (7.8) | 7 (10.8) | 3 (4.8) | ||
| Normal | 77 (60.2) | 44 (67.7) | 33 (52.4) | ||
| High | 41 (32.0) | 14 (21.5) | 27 (42.9) | 0.026 | |
|
Total (n = 600) |
South Asian (n = 380) |
White British (n = 220) |
|||
| Time-point | Age (y) | 3.4 ± 0.8 | 3.4 ± 0.9 | 3.2 ± 0.7 | < 0.001 |
| Weight statusb (n (%)) | |||||
| Underweight | 23 (4.7) | 19 (5.9) | 4 (2.4) | ||
| Healthy weight | 371 (76.0) | 251 (77.4) | 120 (73.2) | ||
| Overweight or obese | 94 (19.3) | 54 (16.7) | 40 (24.4) | 0.014 | |
|
Total (n = 3181) |
South Asian (n = 2011) |
White British (n = 1170) |
|||
| Daily | Wear time (min/d) | 603.8 (199.3) | 604.3 (208.3) | 601.9 (181.8) | 0.051 |
| Type of day (n (%)) | |||||
| Weekday | 2418 (76.0) | 1524 (75.8) | 894 (76.4) | ||
| Weekend | 763 (24.0) | 487 (24.2) | 276 (23.6) | 0.69 | |
| Season (n (%)) | |||||
| Winter | 647 (20.3) | 365 (18.2) | 282 (24.1) | ||
| Spring | 729 (22.9) | 404 (20.1) | 325 (27.8) | ||
| Summer | 609 (19.1) | 380 (18.9) | 229 (19.6) | ||
| Autumn | 1196 (37.6) | 862 (42.9) | 334 (28.6) | < 0.001 | |
| Inactive (n (%))c | 2073 (65.2) | 1284 (63.9) | 789 (67.4) | 0.21 | |
Ethnic differences were analysed using chi-square tests at the participant level; linear and ordered logistic regression with a random intercept to account for clustering within children at the time-point level; linear and ordered logistic regression with two random intercepts to account for days nested within measurement time-points clustered within children at the daily level. Wear time was skewed and was natural log transformed prior to analysis, and median (iqr) rather than mean ± standard deviation values are presented. aBased on the national measure of relative deprivation for small areas in England. bBased on British growth reference data. cInactive was defined as failing to meet the new international guideline daily amount of physical activity for children aged 3 to 4 years (≥180 min of total physical activity including ≥60 min MVPA). South Asian ethnicity includes Pakistani (n = 154), Bangladeshi (n = 21), Indian (n = 4), and ‘Other South Asian’ including specific country of origin unknown (n = 23). MVPA, moderate-to-vigorous physical activity