Table 5.

Multivariate Linear Regression Predicting IRT-Adjusted Sum Physical Difficulty Score

	Change in IRT-Adjusted Sum Physical Difficulty Scoreg
	Model 1a	P Value	Model 2b	P Value
AMD status
None	Reference	—	Reference	—
Early AMD	0.3 (−0.2 to 0.7)c	.20	0.3 (−0.2 to 0.7)	.21
Late AMD	1.7 (0.3 to 3.0)	.02	1.1 (−0.3 to 2.6)	.12
Age category
40–49	Reference	—	Reference	—
50–59	0.1 (−0.2 to 0.3)	.63	0.0 (−0.2 to 0.3)	.64
60–69	−0.5 (−0.8 to −0.2)	.002	−0.5 (−0.8 to −0.2)	.001
≥70	0.0 (−0.2 to 0.3)	.79	−0.1 (−0.4 to 0.1)	.27
Gender
Male	Reference	—	Reference	—
Female	0.3 (0.1 to 0.4)	.004	0.2 (0.1 to 0.4)	.009
Ethnicity
Non-Hispanic White	Reference	—	Reference	—
Hispanic/Mexican	−0.3 (−0.6 to 0.0)	.04	−0.3 (−0.6 to −0.1)	.02
Non-Hispanic Black	0.1 (−0.1 to 0.3)	.21	0.1 (−0.1 to 0.3)	.38
Other	0.0 (−0.5 to 0.5)	.90	−0.1 (−0.6 to 0.4)	.76
Education
>High school	Reference	—	Reference	—
High school	0.2 (0.0 to 0.3)	.03	0.2 (0.0 to 0.3)	.03
<High school	0.2 (−0.1 to 0.5)	.12	0.2 (−0.1 to 0.4)	.14
Poverty level
>2× PL	Reference	—	Reference	—
1–2× PL	0.7 (0.4 to 1.0)	<.001	0.7 (0.4 to 0.9)	<.001
<PL	1.1 (0.8 to 1.4)	<.001	1.1 (0.7 to 1.4)	<.001
Comorbidity scored
0	Reference	—	Reference	—
1	0.2 (0.1 to 0.4)	.002	0.2 (0.1 to 0.4)	.001
2	0.7 (0.5 to 1.0)	<.001	0.7 (0.5 to 0.9)	<.001
3–6	2.6 (2.1 to 3.1)	<.001	2.5 (2.0 to 3.0)	<.001
Depressione
No depression	Reference	—	Reference	—
Depression	2.7 (2.0 to 3.3)	<.001	2.6 (2.0 to 3.3)	<.001
pVA (logMAR)f			0.2 (0.1 to 0.3)	<.001

^aModel 1 is partially adjusted for age, gender, ethnicity, education, poverty, comorbidities, and depression.

^bModel 2 is fully adjusted for age, gender, ethnicity, education, poverty, comorbidities, depression, and pVA (logMAR).

^cCoefficient and 95% CI (computed using interview weights to provide estimates for the total US population and age-standardized to the 2000 US census population), representative of difference in sum difficulty score versus those with no AMD, where a positive coefficient corresponds with higher reported difficulty.

^dComorbidity score out of 6 sum points, allocated for self-reported hypertension, diabetes, lung disease, heart disease, stroke, or cancer.

^eDepression classified as Patient Health Questionnaire-9 score of ≥10.

^fLogMAR in 0.1 increments, where logMAR 0 = 20/20.

^gSum physical difficulty score out of 36 points. Ethnicity (other), Asian or mixed ethnicity; logMAR, logarithm of the minimum angle of resolution; PL, poverty level.