Table 4

Mean values of J₄₅ vector by autorefraction and retinoscopy in different age groups, and by categories of refractive error, Shahroud, Iran, 2015

Grouping v ariables	n	Autorefraction	Retinoscopy	Differences	P value*	PCC	P value†	95% LOA
Age (years)
6	210	0.022±0.10	0.012±0.08	0.010	0.004	0.850	<0.001	−0.09 to 0.11
7	781	0.016±0.13	0.010±0.12	0.006	<0.001	0.926	<0.001	−0.09 to 0.11
8	919	0.010±0.11	0.008±0.09	0.002	0.094	0.873	<0.001	−0.10 to 0.11
9	961	0.015±0.11	0.010±0.11	0.005	0.003	0.903	<0.001	−0.09 to 0.10
10	802	0.011±0.13	0.008±0.11	0.003	0.065	0.924	<0.001	−0.09 to 0.10
11	824	0.015±0.13	0.007±0.11	0.008	<0.001	0.913	<0.001	−0.10 to 0.11
12	556	0.017±0.14	0.015±0.14	0.002	0.369	0.930	<0.001	−0.10 to 0.11
Spherical category
≤−2	63	0.189±0.45	0.183±0.46	0.006	0.606	0.980	<0.001	−0.18 to 0.19
−0.5 to −2	162	0.069±0.29	0.073±0.28	−0.004	0.486	0.953	<0.001	−0.18 to 0.17
−0.49 to 0.49	715	0.009±0.14	0.005±0.13	0.004	0.019	0.927	<0.001	−0.10 to 0.11
0.5 to 2	3933	0.010±0.09	0.004±0.07	0.006	<0.001	0.844	<0.001	−0.09 to 0.10
≥=2	180	0.023±0.14	0.017±0.12	0.006	0.100	0.936	<0.001	−0.10 to 0.11
Total population	5053	0.014±0.12	0.009±0.11	0.005	<0.001	0.910	<0.001	−0.10 to 0.11

*The P value calculated by paired t-test.
†The P value for correlation.
LOA, limit of agreement; PCC, Pearson’s correlation coefficient.