Table 1 General and socioeconomic characteristics of the study population, in total and by district
|  | Total (n = 83) | Low-SES (n = 38) | High-SES (n = 45) | p - value | |
|---|---|---|---|---|---|
Age, mean (SD) | years | 8.5 (0.3) | 8.5 (0.3) | 8.5 (0.3) | 0.603** |
Sex, n (%) | boys | 43 (51.8) | 23 (60.5) | 20 (44.4) | 0.107* |
girls | 40 (48.2) | 15 (39.5) | 25 (55.6) | ||
Body height, mean (SD) | cm | 133.4 (5.6) | 134.2 (6.1) | 132.6 (5.1) | 0.196** |
Body weight, median (IQR) | kg | 28.6 (25.6 - 32.5) | 30.1 (25.9 - 34.2)) | 27.2 (25.5 - 30.6) | 0.088*** |
BMI, median (IQR) | kg/m-2 | 16.1 (15.1 - 17.4) | 16.5 (15.3 - 18.1) | 15.7 (15.0 - 17.1) | 0.131*** |
Daily wear time, median (IQR) | hours | 12.6 (11.8 - 13.3) | 12.6 (12.1 - 13.4) | 12.7 (11.5 - 13.3) | 0.672*** |
Daily time of combined data, median (IQR) | hours | 9.4 (7.9 - 10.3) | 9.3 (7.8 - 10.3) | 9.5 (8.1 - 10.4) | 0.315*** |
Availability of GPS data, median (IQR) | % | 75.8 (66.9 - 83.9) | 73.8 (63.4 - 80.6) | 78.4 (68.3 - 84.7) | 0.113*** |
Wear days (daily wear time ≥1 h), median (IQR) | number | 7.0 (7.0 - 7.0) | 7.0 (7.0 - 7.0) | 7.0 (7.0 - 7.0) | 0.243*** |
Valid days (daily combined data ≥9 h, median (IQR) | number | 5.0 (3.0 - 6.0) | 4.5 (2.8 - 6.0) | 5.0 (3.0 - 6.0) | 0.823*** |
Language spoken at home, n (%) | German | 48 (57.8) | 13 (34.2) | 35 (77.8) | <0.001* |
German and other | 22 (26.5) | 16 (42.1) | 6 (13.3) | ||
other | 12 (14.5) | 9 (23.7) | 3 (6.7) | ||
n/a | 1 (1.2) | 0 (0.0) | 1 (2.2) | ||
Nationality, n (%) | Swiss | 41 (49.4) | 13 (34.2) | 28 (62.2) | 0.030* |
double citizen | 25 (30.1) | 15 (39.5) | 10 (22.2) | ||
non-Swiss | 16 (19.3) | 10 (26.3) | 6 (13.3) | ||
n/a | 1 (1.2) | 0 (0.0) | 1 (2.2) | ||
Parental monthly income, n (%) | ≤ CHF 4000 | 5 (6.0) | 4 (10.5) | 1 (2.2) | 0.026* |
CHF 4001 – 6000 | 13 (15.7) | 8 (21.1) | 5 (11.1) | ||
CHF 6001 – 8000 | 12 (14.5) | 7 (18.4) | 5 (11.1) | ||
CHF 8001 – 12’000 | 22 (26.5) | 10 (26.3) | 12 (26.7) | ||
≥ CHF 12’000 | 20 (24.1) | 3 (7.9) | 17 (37.8) | ||
n/a | 11 (13.3) | 6 (15.8) | 5 (11.1) | ||
Highest parental education, n (%) | compulsory/basic | 4 (4.8) | 4 (10.5) | 0 (0.0) | <0.001* |
upper secondary | 20 (24.1) | 18 (47.4) | 2 (4.4) | ||
tertiary/higher | 58 (69.9) | 16 (42.1) | 42 (93.3) | ||
n/a | 1 (1.2) | 0 (0.0) | 1 (2.2) | ||
Sports club membership, n (%) | yes | 43 (51.8) | 18 (47.4) | 25 (55.6) | 0.576* |
no | 39 (47.0) | 20 (52.6)) | 19 (42.2) | ||
n/a | 1 (1.2) | 0 (0.0) | 1 (2.2) | ||