Table 1 Characteristics of participants aged 5–12 years according to the refractive error status in the right eye
Total | Myopia (SE ≤ − 0.50 D) | Emmetropia (− 0.50 < SE < + 0.75 D) | Hyperopia (SE ≥ + 0.75 D) | p-value | |
|---|---|---|---|---|---|
Number | 24,345 | 14,944 (61.38%) | 7790 (32.00%) | 1611 (6.62%) | |
Age (years) | < .0001 | ||||
Mean (SD) | 9.00 (1.94) | 9.58 (1.84) | 8.17 (1.74) | 7.60 (1.64) | |
Gender, n (%) | < .0001 | ||||
Male | 12,620 (51.84%) | 7723 (51.68%) | 3789 (48.64%) | 1108 (68.78%) | |
Female | 11,725 (48.16%) | 7221 (48.32%) | 4001 (51.36%) | 503 (31.22%) | |
Refractive error (SE) (D) | < .0001 | ||||
Mean (SD) | − 1.33 (1.86) | − 2.37 (1.55) | + 0.01 (0.29) | + 1.84 (1.04) | |
BMI (kg/m2) | 0.0315 | ||||
Mean (SD) | 17.82 (3.23) | 18.16 (3.18) | 17.32 (3.22) | 17.13 (3.23) | |
Parental myopia, n (%) | < .0001 | ||||
Father | 4492 (18.45%) | 2824 (18.90%) | 1499 (19.24%) | 169 (10.49%) | |
Mother | 5407 (22.21%) | 3342 (22.36%) | 1806 (23.18%) | 259 (16.08%) | |
Both parents | 6804 (27.95%) | 4676 (31.29%) | 1850 (23.75%) | 278 (17.26%) | |
Neither of the parents | 7642 (31.39%) | 4102 (27.45%) | 2635 (33.83%) | 905 (56.18%) | |
Near work, n (%) | < .0001 | ||||
≤ 2 h/day | 12,174 (50.01%) | 7226 (48.35%) | 4171 (53.54%) | 777 (48.23%) | |
3 h/day | 5991 (24.61%) | 4006 (26.81%) | 1714 (22.00%) | 271 (16.82%) | |
≥ 4 h/day | 6180 (25.39%) | 3712 (24.84%) | 1905 (24.45%) | 563 (34.95%) | |
Household income, n (%) | < .0001 | ||||
Low | 1277 (5.25%) | 681 (4.56%) | 523 (6.71%) | 73 (4.53%) | |
Middle | 14,030 (57.63%) | 8310 (55.61%) | 4459 (57.24%) | 1261 (78.27%) | |
High | 9038 (37.12%) | 5953 (39.84%) | 2808 (36.05%) | 277 (17.19%) | |
Residence, n (%) | < .0001 | ||||
Urban | 16,005 (65.74%) | 9947 (66.56%) | 5165 (66.30%) | 893 (55.43%) | |
Rural | 8340 (34.26%) | 4997 (33.44%) | 2625 (33.70%) | 718 (44.57%) | |
Second hand smoking exposure, n (%) | < .0001 | ||||
Yes | 1073 (4.41%) | 486 (3.25%) | 514 (6.60%) | 73 (4.53%) | |
No | 6306 (25.90%) | 3511 (23.49%) | 2205 (28.31%) | 590 (36.62%) | |
No one smokes indoors regularly at home | 16,966 (69.69%) | 10,947 (73.25%) | 5,071 (65.10%) | 948 (58.85%) | |
Urine cotinine level (µg/mL) | < .0001 | ||||
Mean (SD) | 0.46 (0.68) | 0.46 (0.81) | 0.43 (0.40) | 0.56 (0.41) |