. 2022 Jan 22;2(1):100113. doi: 10.1016/j.xops.2022.100113

Table 4.

Distribution of Axial Length by Educational Background

Variable	Community-Based Cohort (N = 22 379) Discovery Stage					P Value^∗	P for Trend^†	Kendall's Rank Correlation Tau (P Value)
Educational Background	Elementary School, Junior High School	High School	Vocational School, College, Technical College	University	Graduate School	P Value^∗	P for Trend^†	Kendall's Rank Correlation Tau (P Value)
Education duration (yrs)	6–9	12	14	16	18–21
N	2165	11 533	5743	2791	147
(Male/female)	(895/1270)	(3494/8039)	(846/4897)	(1473/1318)	(83/64)
Mean age (yrs)	69.02	63.02	58.45	58.63	53.34
SD	9.27	11.35	12.61	14.36	15.91
Right AL (mm)^‡	23.80	23.95	23.99	24.24	24.39	<0.0001	0.0001	0.17 (P < 0.0001)
95% CI	[23.78–23.81]	[23.95–23.96]	[23.98–24.01]	[24.22–24.25]	[24.31–24.47]	<0.0001	0.0001	0.17 (P < 0.0001)
Left AL (mm)^‡	23.76	23.92	23.96	24.20	24.35	<0.0001	0.0001	0.17 (P < 0.0001)
95% CI	[23.74–23.78]	[23.91–23.92]	[23.95–23.97]	[24.19–24.22]	[24.27–24.43]	<0.0001	0.0001	0.17 (P < 0.0001)

Variable	Birth and Three-Generation Cohort (N =11 104) Validation Stage					P Value^∗	P for Trend^†	Kendall's Rank Correlation Tau (P Value)
Educational Background	Elementary School, Junior High School	High School	Vocational School, College, Technical College	University	Graduate School	P Value^∗	P for Trend^†	Kendall's Rank Correlation Tau (P Value)
Education duration (yrs)	6–9	12	14	16	18–21
N	541	4293	3321	2676	273
(Male/female)	(251/290)	(1605/2688)	(711/2610)	(1252/1424)	(175/98)
Mean age, yrs	50.58	45.05	41.11	39.59	39.03
SD	17.29	14.67	12.21	11.74	9.16
Right AL (mm)^‡	24.31	24.48	24.51	24.68	24.79	<0.0001	0.0001	0.15 (P < 0.0001)
95% CI	[24.26–24.36]	[24.47–24.50]	[24.50–24.53]	[24.67–24.70]	[24.75–24.83]	<0.0001	0.0001	0.15 (P < 0.0001)
Left AL (mm)^‡	24.28	24.45	24.47	24.64	24.75	<0.0001	0.0001	0.15 (P < 0.0001)
95% CI	[24.23–24.32]	[24.43–24.46]	[24.46–24.49]	[24.63–24.66]	[24.71–24.80]	<0.0001	0.0001	0.15 (P < 0.0001)

Elementary School, Junior High School: <9 years of school; High School: 12 years of school; Vocational School, College, Technical College: 16 years of school; University: 16 years of school; Graduate School: ≥18 years of school.

AL = axial length; CI = confidence interval; SD = standard deviation.

^∗

One-way analysis of variance was performed after adjusting for age and sex.

^†

Jonckheere-Terpstra test (number of permutations for the reference distribution = 10 000).

^‡

Adjusted for sex, age, and height.