Table 2. Prevalence of Myopia (SER ≤ −0.5D) for Each Year in School-Aged Children.
| Age, y | No. | Prevalence per year, % | P valuea | |||||
|---|---|---|---|---|---|---|---|---|
| 2015 | 2016 | 2017 | 2018 | 2019 | 2020 | |||
| 6 | 22 082 | 3.5 | 4.3 | 4.5 | 5.4 | 5.7b | 21.5 | <.001 |
| 7 | 27 979 | 10.8 | 11.7 | 12.1 | 16.2b | 13.6 | 26.2 | <.001 |
| 8 | 25 877 | 22.0 | 22.4 | 27.2 | 27.7b | 26.3 | 37.2 | <.001 |
| 9 | 23 591 | 35.4 | 36.1 | 40.8 | 43.5b | 38.8 | 45.3 | .09 |
| 10 | 22 910 | 48.3 | 51.4 | 51.3 | 55.1b | 50.7 | 52.8 | .03 |
| 11 | 25 373 | 63.3b | 61.1 | 61.6 | 62.0 | 62.5 | 59.5 | .004 |
| 12 | 22 742 | 75.5b | 67.5 | 66.6 | 68.9 | 69.8 | 67.1 | <.001 |
| 13 | 24 350 | 80.0 | 78.4 | 79.3 | 84.9b | 82.1 | 81.5 | <.001 |
Abbreviation: SER, spherical equivalent refraction.
a
P value was calculated using 2-proportions z test, comparing the prevalence in 2020 with the highest prevalence in the relative age group in 2015-2019.
b
Highest prevalence within the age group during the 2015-2019 screening.