Longitudinal association between myopia and parental myopia and outdoor time among students in Wenzhou: a 2.5-year longitudinal cohort study

Table 2 Univariate Results for Refractive Error, Time Activities, and Parental history for children myopia change

Variable	Initial and final non-myopia (n = 803)	New onset myopia (n = 307)	statistics †	p value ‡
Baseline SER, mean ± SD, D	0.15 ± 0.55	−0.28 ± 0.42	12.418	< 0.001
Baseline AL, mean ± SD, mm	22.83 ± 0.72	23.15 ± 0.74	−6.629	< 0.001
Baseline AL/CRC ratio, mean ± SD	2.92 ± 0.06	2.98 ± 0.06	−13.992	< 0.001
Mean myopia progression, mean ± SD, D/y	−0.03 ± 0.23	−0.60 ± 0.36	31.459	< 0.001
Mean AL change, mean ± SD, mm/y	0.17 ± 0.08	0.36 ± 0.12	−29.903	< 0.001
Near work time, mean ± SD, h/day	3.25 ± 0.94	3.23 ± 0.87	0.374	0.708
Outdoor time, mean ± SD, h/day	1.92 ± 0.76	1.81 ± 0.71	2.295	0.022
Number of myopic parents
0	(191)23.8%	(47)15.3%	87.126	< 0.001
1	(336)41.8%	(102)33.2%	125.014	< 0.001
2	(276)34.4%	(158)51.5%	32.083	< 0.001

† Statistics for children with no-myopia at baseline
‡ Chi square test was used in classification variable comparisons, independent t-test was used in continuous variable comparisons

ISSN: 1471-2415