Table 1 Baseline Demographics of Study Participants
Characteristics | Total (n = 311) | Anonymous arm (n = 155) | Onymous arm (n = 156) | p-value |
|---|---|---|---|---|
Age, Mean ± SD | 14.6 ± 1.0 | 14.7 ± 1.0 | 14.6 ± 1.0 | 0.799 |
Gender, N (%) | ||||
 Female | 211 (67.9) | 108 (69.7) | 103 (66.0) | 0.491 |
Ethnicity, N (%) | ||||
 Chinese | 278 (89.4) | 136 (87.7) | 142 (91.0) | 0.767 |
 Malay/Indian/Others | 33 (10.6) | 19 (12.3) | 14 (9.0) | |
Grade, N (%) | ||||
 Secondary 1 | 18 (5.8) | 10 (6.5) | 8 (5.1) | 0.493 |
 Secondary 2 | 61 (19.7) | 27 (17.5) | 34 (21.8) | |
 Secondary 3 | 98 (31.6) | 54 (35.1) | 44 (28.2) | |
 Secondary 4 | 133 (42.9) | 63 (40.9) | 70 (44.9) | |
Hours spent outdoors (Median, IQR) | ||||
 School day | 2.5 (2.5–5.5) | 2.5 (1.5–4.5) | 3.5 (2.5–5.5) | 0.212 |
 Weekend | 3.5 (1.5–5.5) | 3.5 (1.5–5.5) | 3.5 (1.5–7.5) | 0.237 |
Time spent on sports or exercise while staying outdoors (hours), N (%) | ||||
 School day | ||||
  None | 9 (2.89) | 4 (2.6) | 5 (3.2) | 0.802 |
  Less than 1 h | 161 (51.8) | 83 (53.6) | 78 (50.0) | |
  More than 1 h | 141 (45.3) | 68 (43.9) | 73 (46.8) | |
 Weekend | ||||
  None | 38 (12.4) | 15 (9.9) | 23 (14.9) | 0.369 |
  Less than 1 h | 155 (50.7) | 81 (53.3) | 74 (48.1) | |
  More than 1 h | 113 (36.9) | 56 (36.8) | 57 (37.0) | |