Table 1.
Subject characteristics
| EE | EL | LE | LL | All | P-value | |
|---|---|---|---|---|---|---|
| n = 719 | n = 453 | n = 378 | n = 650 | n = 2200 | ||
| Boys | 356 | 221 | 182 | 327 | 1086 | |
| Girls | 363 | 232 | 196 | 323 | 1114 | |
| Age (years) | 13.4 (2.2) | 13.5 (2.2) | 13.2 (2.3) | 13.6 (2.2) | 13.4 (2.2) | 0.21 |
| BMI (kg/m2) | 20.4 (4.0) | 20.5 (3.8) | 20.8 (4.0) | 21.2 (4.3) | 20.7 (4.1) | 0.002 |
| % Obese | 4.6 | 5.7 | 7.1 | 8.8 | 6.5 | 0.001 |
| % Overweight (not including obese) | 16.8 | 19.2 | 22.0 | 19.7 | 19.0 | 0.01 |
| SEIFA | 1002 (59) | 1004 (67) | 1003 (62) | 999 (71) | 1002 (65) | 0.58 |
| Household income (%) | ||||||
| > AUD104,000 | 30.0 | 27.9 | 32.4 | 29.2 | 29.7 | |
| AUD75,000-104,000 | 21.7 | 16.4 | 17.2 | 20.1 | 19.4 | |
| AUD52,000-75,000 | 20.7 | 21.5 | 25.9 | 18.3 | 21.1 | |
| < AUD52,000 | 27.6 | 34.2 | 24.5 | 32.3 | 29.8 | 0.01 |
| Remoteness (%) | ||||||
| Major city | 47.7 | 58.3 | 56.9 | 61.5 | 55.5 | |
| Inner regional | 26.3 | 20.5 | 18.5 | 18.9 | 21.6 | |
| Outer regional | 20.2 | 16.1 | 19.6 | 15.5 | 17.9 | |
| Remote | 5.8 | 5.1 | 5.0 | 4.0 | 5.0 | 0.0002 |
| Number of children in home | 2.2 | 2.1 | 2.1 | 2.1 | 2.1 | 0.006 |
| Young person in part-time work (min/d) | 8.0 | 6.0 | 14.0 | 10.0 | 9.2 | 0.003 |
Values are shown as percentages or means (SDs).
EE, Early-bed/Early-rise; EL, Early-bed/Late-rise; LE, Late-bed/Early-rise; LL, Late-bed/Late-rise; BMI, body mass index; SEIFA, Socioeconomic indicators for areas. SEIFA is a series of indices of socioeconomic status devised by the Australian Bureau of Statistics using a range of indicators such as educational and employment status.
The index used here is the Index of Relative Disadvantage, calculated at the postal area level. The national average is 1000 and the SD is 100. Higher values indicate more advantaged areas.