Refractive and corneal astigmatism in Chinese 4–15 years old children: prevalence and risk factors

BMC Ophthalmology

Table 3 Prevalence of RA and CA by different learning stages and gender

Variables	N	RA		^‡P value	CA		^‡P value
Variables	N	N	% (95% CI)	^‡P value	N	% (95% CI)	^‡P value
Total		1440	20.3 (19.3–21.3)		4792	67.6 (66.6–68.7)
Age(year)
kindergarten
Total	2045	324	15.8 (14.3–17.4)^a		1309	64 (61.9–66.3)^a
4	911	154	16.9 (14.5–19.4)	0.053	610	67.0 (64–70)	0.045
5	957	134	14.0 (11.9–16.1)		590	61.7 (58.6–64.8)
6	177	36	20.3 (14.7–26.6)		109	61.6 (53.7–68.9)
Primary school
Total	3296	545	16.5 (15.2–17.8)^a		2142	65 (63.4–66.7)^a
6	641	88	13.7 (11.1–16.5)	< 0.001	390	60.8 (56.8–64.6)	< 0.001
7	851	123	14.5 (12.1–16.8)		524	61.6 (58.2–64.9)
8	752	118	15.7 (13.2–18.5)		490	65.2 (62.0–68.5)
9	506	89	17.6 (14.2–20.9)		353	69.8 (65.8–73.3)
10	463	112	24.2 (20.5–28.1)		331	71.5 (67.4–75.6)
11	83	15	18.1 (9.6–27.7)		54	65.1 (54.2–74.7)
Junior high school
Total	1743	571	32.8 (30.5–34.7)^b		1341	76.9 (74.9–78.8)^b
11	384	115	29.9 (25.3–34.6)	0.031	295	76.8 (72.9–81.0)	0.836
12	512	154	30.1 (26.0–34.0)		395	77.1 (73.6–80.7)
13	448	147	32.8 (28.6–37.3)		347	77.5 (73.4–81.0)
14	326	130	39.9 (35.0–45.1)		252	77.3 (73.0–81.9)
15	73	25	34.2 (23.3–45.2)		52	71.2 (61.6–80.8)
^†P value			<0.001			<0.001
Gender
Boy	3663	797	21.8 (20.3–23.1)	0.002	2392	65.3 (63.7–66.9)	0.001
Girl	3421	643	18.8 (17.5–20.2)	0.002	2400	70.2 (68.6–71.7)	0.001

RA, refractive astigmatism; CA, corneal astigmatism;^†P, the chi-square test comparing the prevalence of RA and CA across three learning stages; ^a and ^b, statistical difference in post hoc comparisons; ^‡P, the chi-square test comparing the prevalence of RA and CA across different age groups within various learning stages and between boys and girls

ISSN: 1471-2415