|  | Dry eyes | |||||
---|---|---|---|---|---|---|---|
Item | Â | Â | Not dry | Dry | Â | ||
 |  |  | mean | SE | mean | SE | P-valuea |
Age | Â | Â | 8.98 | 0.023 | 9.44 | 0.048 | Â |
Height |  |  | 134.1 | 0.16 | 136.8 | 0.32 | < 0.001 |
Weight |  |  | 30.1 | 0.11 | 31.9 | 0.24 | < 0.001 |
 |  | N | n | % | N | % | P-valueb |
Gender | Boys | 3611 | 2921 | 80.9 | 690 | 19.1 | 0.25 |
Girls | 3430 | 2811 | 82.0 | 619 | 18.0 | Â | |
School year | 1 | 1385 | 1208 | 87.2 | 177 | 12.8 | < 0.001 |
2 | 1280 | 1073 | 83.8 | 207 | 16.2 | Â | |
3 | 1219 | 1007 | 82.6 | 212 | 17.4 | Â | |
4 | 1179 | 934 | 79.2 | 245 | 20.8 | Â | |
5 | 1114 | 870 | 78.1 | 244 | 21.9 | Â | |
6 | 864 | 640 | 74.1 | 224 | 25.9 | Â |