| |
Item content
|
Subgroups
|
α
|
β
1
|
β
2
|
β
3
|
β
4
|
β
5
|
G2
|
df
|
p
|
ESΔmax
|
θ
|
|---|
|
Basic aspects
| | | | | | | | | | | | |
|
7.
|
Eyes getting tired
|
Low vision
|
2.50
|
-0.93
|
-0.65
|
-0.10
|
0.32
|
2.13
|
15.7
|
5
|
0.008
|
-0.80
|
-0.80
|
| | |
Moderate vision loss
|
2.50
|
-1.37
|
-1.23
|
-0.54
|
0.10
|
1.86
| | | | | |
|
Mobility
| | | | | | | | | | | | |
|
3.
|
Seeing steps or curbs*
|
Low vision
|
2.38
|
-0.97
|
-0.61
|
-0.01
|
0.21
|
1.56
|
14.2
|
1
|
< 0.001
|
-0.74
|
0.20
|
| | |
Moderate vision loss
|
5.76
|
-0.96
|
-0.71
|
-0.26
|
-0.02
|
1.68
| | | | | |
|
Adjustment
| | | | | | | | | | | | |
|
1.
|
Vision in general
|
Self
|
1.99
|
-1.98
|
-1.44
|
-0.14
|
0.38
|
2.33
|
19.4
|
5
|
0.002
|
-0.70
|
-2.00
|
| | |
Assisted
|
1.99
|
-2.47
|
-2.30
|
-0.56
|
-0.09
|
2.33
| | | | | |
|
1.
|
Vision in general
|
Male
|
2.08
|
-2.05
|
-1.44
|
0.04
|
0.40
|
1.95
|
17.9
|
5
|
0.003
|
0.62
|
2.60
|
| | |
Female
|
2.08
|
-1.83
|
-1.57
|
-0.27
|
0.24
|
3.37
| | | | | |
|
12.
|
Unhappy situation in life†
|
Male
|
3.27
|
-0.74
|
-0.31
|
0.56
|
1.03
|
3.06
|
15.4
|
5
|
0.009
|
1.00
|
5.40
|
| | |
Female
|
3.27
|
-0.39
|
-0.27
|
0.51
|
0.88
|
7.57
| | | | | |
|
Reading and fine work
| | | | | | | | | | | |
|
19.
|
Reading labels
|
AMD
|
3.77
|
-1.34
|
-1.21
|
-0.94
|
-0.46
|
0.68
|
17.8
|
5
|
0.003
|
0.24
|
-0.80
|
| | |
Other
|
3.77
|
-1.48
|
-1.16
|
-0.63
|
-0.51
|
0.68
| | | | | |
|
24.
|
Using tools
|
Male
|
1.83
|
-1.22
|
-0.92
|
-0.38
|
-0.15
|
1.13
|
35.2
|
5
|
< 0.001
|
-1.22
|
-1.00
|
| | |
Female
|
1.83
|
-1.80
|
-1.58
|
-1.39
|
-0.94
|
1.05
| | | | | |
- Person distribution standard normal; α = item discrimination parameter; β = item threshold parameter; G2 = Chi-square statistic; df = degrees of freedom; ESΔmax = maximum difference in expected scores, θ = person parameter (disability level is presented at which the maximum difference in expected scores was found); AMD = age-related macular degeneration.
- * Non-uniform DIF; † After deleting item 1, DIF for item 12 was not statistically significant.
