Reliability and validity of the National Eye Institute Visual Function Questionnaire-25 in patients with age-related macular degeneration.

PURPOSE: To evaluate the psychometric characteristics of the National Eye Institute Visual Function Questionnaire-25 (NEI VFQ-25) in patients with age-related macular degeneration (AMD) who participated in two clinical trials. METHODS: A secondary analysis of data from two randomized clinical trials was performed. NEI VFQ-25 data were collected from 1134 of 1146 patients with subfoveal choroidal neovascularization due to AMD with minimally classic or occult with no classic types and predominantly classic type. The NEI VFQ-25 was administered at baseline and months 1, 2, 3, 6, 9, and 12, and the SF-36 Health survey was administered at baseline and months 6 and 12. Visual acuity assessments were completed monthly throughout the studies. Internal consistency reliability and construct validity were examined. RESULTS: The average age was 77 years (SD = 7.5; range, 52-96) with 59% women. At baseline, internal consistency reliability was 0.96 for the NEI VFQ-25 total score and ranged from 0.62 (ocular pain) to 0.91 (near activities) for the subscales. NEI VFQ-25 total and subscale scores correlated significantly with SF-36 scores (P < 0.05), and total, near activities, distance activities, and dependency scores correlated significantly with best corrected visual acuity (BCVA) in the better (P < 0.0001) and worse seeing eye (P < 0.0001). Mean NEI VFQ-25 total and subscale scores, except for ocular pain and general health, varied by BCVA group (P < 0.001), with higher impairment scores seen in the lower visual acuity groups. CONCLUSIONS: The NEI VFQ-25 demonstrated good reliability and construct validity as a measure of vision-related functioning outcomes in patients with AMD.

The impact of somatic and cognitive disorders on the functional status of the elderly.

To estimate the relative effects of coexisting nondementia illnesses on the probability of functional disability, depending on the presence of cognitive impairment or dementia, we used data from the baseline case-control assessment of a longitudinal study of aging and dementia. Our study included 668 subjects (345 nondemented, 98 cognitively impaired, and 225 demented), aged 75 and older. Demented subjects had greater disability prevalence on all specific instrumental activities of daily living (IADL) and activities of daily living (ADL) items than cognitively impaired subjects who, in turn, had greater disability than nondemented subjects. Somatic illnesses were found to be associated with particular tasks in item specific models; decreasing MMSE was strongly associated with the probability of IADL and ADL disability, which increased dramatically in the presence of somatic illnesses among cognitively impaired as well as demented subjects. Attention to illnesses among cognitively impaired and demented people may shed light on remediable factors crucial to their daily functioning.