Table 3. Multilinear regression of total academic performance and exact eye refraction stratified by refractive status in Yangjiang cohort.

Grade	Hyperopia				Myopia
	N	β	P value		N	β	P value
1	21	<0.001	1.00		34	0.002	0.81
2	10	0.04	0.31		36	−0.01	0.57
3	4	NA	NA		46	−0.02	0.08
4	6	−0.02	0.83		83	0.01	0.18
5	4	NA	NA		128	−0.01	0.35
6	3	NA	NA		175	−0.01	0.18
7	5	−0.27	0.77		175	−0.002	0.77
8	2	NA	NA		113	−0.01	0.19
9	0	NA	NA		93	−0.02	0.02

NA: not available (lacking an adequate sample size for statistical analyses).