Table 1.
Characteristics of all participants
| Characteristics | All participants (586) |
Subgroup participants | P value | |||
|---|---|---|---|---|---|---|
| Non-myopia (360) | Myopia (226) | |||||
| Age | P < 0.001** | |||||
| 6–8 years | 333 | 268 (80.48%) | 65 (19.52%) | |||
| 9–12 years | 253 | 92 (36.36%) | 161 (63.64%) | |||
| Sex | P = 0.001** | |||||
| Female | 273 | 148 | (54.21%) | 125 | (45.79%) | |
| Male | 313 | 212 | (67.73%) | 101 | (32.27%) | |
| Duration of electronic device use per week | P = 0.078 | |||||
| 0–7 h | 328 | 213 | (64.94%) | 115 | (35.06%) | |
| 7–14 h | 184 | 110 | (59.78%) | 74 | (40.22%) | |
| 14–21 h | 50 | 27 | (54.00%) | 23 | (46.00%) | |
| >21 h | 24 | 10 | (41.67%) | 14 | (58.33%) | |
| Duration of watching television per week | P = 0.594 | |||||
| 0–7 h | 416 | 250 | (60.10%) | 166 | (39.90%) | |
| 7–14 h | 126 | 84 | (66.67%) | 42 | (33.33%) | |
| 14–21 h | 30 | 18 | (60.00%) | 12 | (40.00%) | |
| >21 h | 14 | 8 | (57.14%) | 6 | (42.86%) | |
| Duration of near work per week | P < 0.001** | |||||
| 0–25 h | 189 | 136 | (71.96%) | 53 | (28.04%) | |
| 25–38 h | 311 | 182 | (58.52%) | 129 | (41.48%) | |
| >38 h | 86 | 42 | (48.84%) | 44 | (51.16%) | |
| Near-work distance | P = 0.017** | |||||
| >33 cm | 283 | 188 | (66.43%) | 95 | (33.57%) | |
| <33 cm | 303 | 172 | (56.77%) | 131 | (43.23%) | |
| Times of eye exercise per week | P = 0.280 | |||||
| 1–5 times | 285 | 183 | (64.21%) | 102 | (35.79%) | |
| 5–10 times | 246 | 140 | (56.91%) | 106 | (43.09%) | |
| 10–20 times | 52 | 35 | (67.31%) | 17 | (32.69%) | |
| >20 times | 3 | 2 | (66.67%) | 1 | (33.33%) | |
| Times of visual fatigue per week | P = 0.021* | |||||
| 0 time | 338 | 221 | (65.38%) | 117 | (34.62%) | |
| 1–5 times | 231 | 134 | (58.01%) | 97 | (41.99%) | |
| 5–10 times | 12 | 4 | (33.33%) | 8 | (66.67%) | |
| > 10 times | 5 | 1 | (20.00%) | 4 | (80.00%) | |
| Reading posture | P = 0.022* | |||||
| Sitting | 365 | 235 | (64.38%) | 130 | (35.62%) | |
| Prone | 175 | 93 | (53.14%) | 82 | (46.86%) | |
| Supine | 46 | 32 | (69.57%) | 14 | (30.43%) | |
| Distance between fingertip and nib | P = 0.082 | |||||
| <1.5 cm | 218 | 124 | (56.88%) | 94 | (43.12%) | |
| >1.5 cm | 368 | 236 | (64.13%) | 132 | (35.87%) | |
| Head angle | P = 0.233 | |||||
| Vertical 0° | 44 | 26 | (59.09%) | 18 | (40.91%) | |
| Left 0°–45° | 217 | 128 | (58.99%) | 89 | (41.01%) | |
| Left 45°–90° | 250 | 165 | (66.00%) | 85 | (34.00%) | |
| Right 0°–45° | 57 | 30 | (52.63%) | 27 | (47.37%) | |
| Right 45°–90° | 18 | 9 | (50%) | 9 | (50%) | |
| Light environment in classroom | P < 0.001** | |||||
| Closed curtains | 92 | 39 | (42.39%) | 53 | (57.61%) | |
| Open curtains | 516 | 335 | (64.92%) | 181 | (35.08%) | |
| Outdoor time per week | P = 0.026* | |||||
| 0–7 h | 268 | 150 | (55.97%) | 118 | (44.03%) | |
| 7–14 h | 257 | 166 | (64.59%) | 91 | (35.41%) | |
| >14 h | 61 | 44 | (72.13%) | 17 | (27.87%) | |
| Parents with myopia | P = 0.002* | |||||
| 0 | 133 | 96 | (72.18%) | 37 | (27.82%) | |
| 1 | 253 | 158 | (62.45%) | 95 | (37.55%) | |
| 2 | 200 | 106 | (53.00%) | 94 | (47.00%) | |
| Parents with high myopia | P = 0.532 | |||||
| 0 | 422 | 257 | (60.90%) | 165 | (39.10%) | |
| 1 | 130 | 79 | (60.77%) | 51 | (39.23%) | |
| 2 | 34 | 24 | (70.59%) | 10 | (29.41%) | |
| Vegetable intake per day | P = 0.852 | |||||
| < 75 g | 179 | 113 | (63.13%) | 66 | (36.87%) | |
| 75–150 g | 312 | 189 | (60.58%) | 123 | (39.42%) | |
| > 150 g | 95 | 58 | (61.05%) | 37 | (38.95%) | |
| Fruit intake per day | P = 0.545 | |||||
| <75 g | 295 | 177 | (60.00%) | 118 | (40.00%) | |
| 75–150 g | 244 | 156 | (63.93%) | 88 | (36.07%) | |
| >150 g | 47 | 27 | (57.45%) | 20 | (42.55%) | |
| Percentage of grains in staple foods | P = 0.052 | |||||
| <25% | 362 | 213 | (58.84%) | 149 | (41.16%) | |
| 25–50% | 179 | 112 | (62.57%) | 67 | (37.43%) | |
| >50% | 45 | 35 | (77.78%) | 10 | (22.22%) | |
| School type | P = 0.107 | |||||
| Public schools | 560 | 348 | (62.14%) | 212 | (37.86%) | |
| Private schools | 26 | 12 | (46.15%) | 14 | (53.85%) | |
*, P < 0.05 is significant; **, P < 0.001 is highly significant