Table 1.

The magnitude of RA and CA by different learning stages and gender

Variables	N	RA	‡P value	CA	‡P value
		Mean ± SD (D)		Mean ± SD (D)
Total	7084	−0.61 ± 0.62		−1.20 ± 0.64
Age(years)
kindergarten
Total	2045	−0.53 ± 0.53a		−1.14 ± 0.63a
4	911	−0.55 ± 0.56	0.132	−1.17 ± 0.64	0.049
5	957	−0.50 ± 0.49		−1.10 ± 0.62
6	177	−0.55 ± 0.59		−1.12 ± 0.61
Primary school
Total	3296	−0.56 ± 0.57a		−1.16 ± 0.62a
6	641	−0.52 ± 0.56	<0.001	−1.14 ± 0.60	0.009
7	851	−0.51 ± 0.52		−1.13 ± 0.62
8	752	−0.52 ± 0.51		−1.17 ± 0.66
9	506	−0.59 ± 0.61		−1.20 ± 0.60
10	463	−0.69 ± 0.68		−1.25 ± 0.62
11	83	−0.57 ± 0.44		−1.10 ± 0.46
Junior high school
Total	1743	−0.81 ± 0.76b		−1.34 ± 0.67b
11	384	−0.76 ± 0.75	0.132	−1.34 ± 0.70	0.354
12	512	−0.77 ± 0.69		−1.31 ± 0.62
13	448	−0.85 ± 0.81		−1.36 ± 0.68
14	326	−0.88 ± 0.83		−1.37 ± 0.69
15	73	−0.77 ± 0.64		−1.23 ± 0.65
†P value	<0.001			<0.001
Gender
Boy	3663	−0.62 ± 0.63	0.015	−1.18 ± 0.66	<0.001
Girl	3421	−0.59 ± 0.61		−1.22 ± 0.61

RA, refractive astigmatism; CA, corneal astigmatism; ^†P, one-way ANOVA comparing RA and CA values across the three learning stages; ^a and ^b, statistical difference in the post hoc comparisons; ^‡P, one-way ANOVA comparing RA and CA values across different age groups within different learning stages or Manner Whitney U Test comparing RA and CA values between boys and girls