Table 3

Mean values of J₀ vector by autorefraction and retinoscopy in different age groups, and by categories of refractive error, Shahroud, Iran, 2015

Grouping variables	n	Autorefraction	Retinoscopy	Differences	P value*	PCC	P value†	95% LOA
Age (years)
6	210	0.170±0.27	0.156±0.27	0.014	0.006	0.966	<0.001	−0.13 to 0.15
7	781	0.155±0.25	0.142±0.24	0.013	<0.001	0.961	<0.001	−0.12 to 0.15
8	919	0.146±0.29	0.138±0.28	0.008	<0.001	0.971	<0.001	−0.13 to 0.14
9	961	0.135±0.27	0.123±0.26	0.012	<0.001	0.968	<0.001	−0.12 to 0.15
10	802	0.112±0.26	0.101±0.25	0.011	<0.001	0.966	<0.001	−0.12 to 0.15
11	824	0.099±0.25	0.089±0.24	0.010	<0.001	0.958	<0.001	−0.13 to 0.15
12	556	0.122±0.35	0.117±0.33	0.005	0.075	0.983	<0.001	−0.12 to 0.13
Spherical category
≤−2	63	0.663±0.71	0.664±0.70	−0.001	0.938	0.987	<0.001	−0.22 to 0.22
−0.5 to −1.99	162	0.438±0.68	0.437±0.68	0.001	0.832	0.994	<0.001	−0.14 to 0.15
−0.49 to 0.49	715	0.101±0.32	0.097±0.31	0.004	0.073	0.978	<0.001	−0.13 to 0.14
0.5 to 1.99	3933	0.109±0.19	0.098±0.18	0.011	<0.001	0.937	<0.001	−0.12 to 0.14
≥2	180	0.26±0.340	0.234±0.33	0.026	<0.001	0.976	<0.001	−0.12 to 0.17
Total Population	5053	0.131±0.28	0.120±0.27	0.011	<0.001	0.969	<0.001	−0.12 to 0.15

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