Table 1 Subject demographic information in the final cohort
Variables | Total (mean or n) | Myopia, mean or n (%) | Non-myopia, mean or n (%) | P |
|---|---|---|---|---|
All subjects | 2221 | 260 (11.7%) | 1961 (88.3%) | Â |
Gender | 0.03 | |||
 Boy | 1156 | 119 (10.3%) | 1037 (89.7%) |  |
 Girl | 1065 | 141 (13.2%) | 924 (86.8%) |  |
Region | 0.05 | |||
 Center city | 1224 | 145 (11.8%) | 1079 (88.2%) |  |
 Non-center city | 997 | 115 (11.5%) | 882 (88.5%) |  |
Age at baseline | 9.06 ± 1.67 | 9.68 ± 1.55 | 8.98 ± 1.67 |  < 0.01 |
Grade at baseline |  < 0.01 | |||
 1 | 317 | 7 (2.2%) | 310 (97.8%) |  |
 2 | 511 | 34 (6.7%) | 477 (93.3%) |  |
 3 | 469 | 62 (13.2%), | 407 (86.8%) |  |
 4 | 380 | 57 (15.0%), | 323 (85.0%) |  |
 5 | 320 | 55 (17.2%) | 265 (82.8%) |  |
 6 | 224 | 45 (20.1%) | 179 (79.9%) |  |