Table 2 The baseline characteristics (percentage and 95% CI) of study children by age group
Sample characteristic of the study child | Age group | |||
|---|---|---|---|---|
10 to 11 | 12 to 13 | 14 to 15 | 16 to 17 | |
Male | ||||
 B cohort | 51.3 (49.6, 53.0) | 51.0 (49.1, 52.9) |  |  |
 K cohort | 51.2 (49.6, 52.8) | 51.8 (50.0, 53.5) | 51.4 (49.7, 53.2) | 51.4 (49.3, 53.5) |
 Born in Australia* | 97.9 (97.5, 98.3) | 98.0 (97.6, 98.4) | 96.2 (95.4, 96.9) | 96.1 (95.1, 96.8) |
 ATSI* | 3.8 (3.2, 4.5) | 3.2 (2.6, 3.9) | 2.6 (2.1, 3.4) | 2.8 (2.1, 3.8) |
 aLanguage* | 10.5 (8.9, 12.4) | 9.9 (8.2, 11.8) | 10.2 (8.5, 12.2) | 9.5 (7.8, 11.4) |
 Greater capital city* | 64.0 (62.3, 65.6) | 63.6 (61.9, 65.2) | 62.9 (60.8, 64.9) | 62.4 (60.1, 64.7) |
 bSEIFA* | 1009.4 (1003.4, 1015.4) | 1005.0 (998.8, 1011.3) | 1007.0 (1000.7, 1013.3) | 1003.7 (996.9, 1010.5) |
Body mass index | ||||
 B cohort | ||||
  Underweight | 6.8 (5.9, 7.8) | 6.5 (5.5, 7.6) |  |  |
  Normal weight | 67.2 (65.3, 69.1) | 66.7 (64.7, 68.6) |  |  |
  Overweight or obese | 26.0 (24.4, 27.7) | 26.9 (25.0, 28.8) |  |  |
 K cohort | ||||
  Underweight | 5.9 (5.1, 6.8) | 6.5 (5.7, 7.4) | 6.3 (5.5, 7.3) | 6.5 (5.5, 7.6) |
  Normal weight | 65.5 (63.6, 67.4) | 65.7 (63.8, 67.5) | 65.1 (63.2, 66.9) | 62.3 (60.1, 64.4) |
  Overweight or Obese | 28.6 (26.8, 30.4) | 27.8 (26.1, 29.6) | 28.6 (26.9, 30.4) | 31.3 (29.2, 33.4) |
Puberty, female study child | ||||
 Menstruation commenced | ||||
  B cohort | 7.7 (6.3, 9.4) | 51.7 (48.6, 54.7) |  |  |
  K cohort | 5.7 (4.5, 7.2) | 57.0 (54.7, 59.3) | 94.6 (93.3, 95.7) | 98.8 (97.7, 99.3) |
 Breast growth | ||||
  B cohort | 42.5 (39.7, 45.3) | 80.7 (78.3, 82.9) |  |  |
  K cohort | 43.3 (40.9, 45.9) | 81.1 (79.1, 83.0) | 87.0 (85.2, 88.7) | 93.6 (91.9, 94.9) |
Puberty, male study child | ||||
 Voice deepened | ||||
  B cohort | 2.3 (1.6, 3.3) | 28.6 (26.0, 31.3) |  |  |
  K cohort | 1.5 (0.9, 2.4) | 24.5 (22.6, 26.5) | 75.4 (73.1, 77.5) | 90.0 (88.1, 91.6) |
 Facial hair | ||||
  B cohort | 1.5 (0.9, 2.3) | 15.0 (13.0, 17.1) |  |  |
  K cohort | 0.9 (0.6, 1.5) | 12.4 (10.8, 14.2) | 49.4 (47.0, 51.8) | 76.4 (73.9, 78.7) |
General health* | ||||
 Excellent | 43.3 (42.0, 44.7) | 44.2 (42.6, 45.7) | 44.5 (42.6, 46.3) | 37.5 (35.4, 39.5) |
 Very Good | 40.2 (39.0, 41.3) | 39.8 (38.5, 41.1) | 37.5 (35.8, 39.2) | 41.1 (39.2, 43.1) |
 Good | 13.8 (12.8, 14.5) | 13.7 (12.8, 14.8) | 13.9 (12.5, 15.4) | 16.9 (15.4, 18.6) |
 Fair | 2.4 (2.0, 2.9) | 2.1 (1.7, 2.5) | 3.3 (2.6, 4.1) | 3.8 (3.1, 4.8) |
 Poor | 0.3 (0.2, 0.5) | 0.2 (0.1, 0.4) | 0.9 (0.6, 1.3) | 0.7 (0.4, 1.0) |