The effect of visual and hearing impairments on functional status

OBJECTIVES: To describe the prevalence of visual and auditory impairment in frail older persons and to evaluate the association between sensory impairment and overall functional status. DESIGN: Prospective patient evaluation and retrospective analysis of data. SETTING: The outpatient geriatric assessment clinic of a university medical center. PARTICIPANTS: Consecutive patients seen in the University of Nebraska Medical Center Outpatient Geriatric Assessment Clinic from 1986 to 1992 for whom both vision and hearing information were available (n = 576). MEASUREMENTS: Visual acuity was measured by the Lighthouse Near Visual Acuity Test, and auditory acuity was evaluated with the whisper test. Functional status was determined by Lawton-Brody activities of daily living (ADL) and instrumental activities of daily living (IADL) scales. Comorbid illness was classified by the Cumulative Illness Rating Scale, and mental status was assessed by the Folstein Mini-Mental State Exam. RESULTS: Eighteen percent of patients had visual impairment of 20/70 or worse. Hearing impairment was found in 64%. The mean ADL and IADL scores were 20/24 and 12/23, respectively, for patients with visual acuity better than 20/70, compared with 18/24 and 8/23 for visually impaired patients (P < .001 for both comparisons). ADL and IADL scores were also higher in hearing intact patients compared with those with hearing impairment: respectively, 21/24 vs 19/24 (P < .001) and 13/23 vs 11/23 (P < .001). The effects of visual acuity and hearing acuity on IADL score are independent of mental status and comorbid illness (P < .001). The effect of visual acuity on ADL score is independent of mental status and comorbid illness (P < .001), whereas the effect of hearing on ADL score is not. Subjects with both hearing and vision impairment had mean IADL (P < = .05) and ADL (P < = .05) scores significantly lower than those with no impairment. CONCLUSIONS: Impairments of vision and hearing are common in this frail older outpatient population. Functional status, as measured by IADL and ADL scores, is diminished for sensory impaired subjects. Combined vision and hearing impairments have a greater effect on function than single sensory impairments and influence functional status independent of mental status and comorbid illness. Overall, these results suggest that interventions to improve sensory function may improve functional independence.