Association between sensory impairment and cognitive frailty among older people: Evidence from four nationwide cohort studies

Sensory impairment, including hearing and vision impairment, are prevalent in older adults and may significantly contribute to cognitive frailty. However, the longitudinal association between sensory impairment and cognitive frailty has not been fully explored. The aim of our study was to examine such associations in four nationally representative cohorts to inform strategies for preventing cognitive frailty and promoting healthy aging. Data were pooled from four large, longitudinal cohorts: the Health and Retirement Study (HRS), the Chinese Longitudinal Healthy Longevity Survey (CLHLS), the Survey of Health, Ageing and Retirement in Europe (SHARE), and the English Longitudinal Study of Ageing (ELSA). The analysis included 37,076 older adults from these cohorts, with comparable measures of sensory impairment and cognitive frailty across studies. Sensory impairments were assessed via self-reported hearing impairment and vision impairment. The outcome was the incidence of cognitive frailty, assessed using self-reported cognitive function and frailty indicators. Cox regression models were used to evaluate the association between hearing impairments, vision impairments and dual sensory impairment with cognitive frailty risk, adjusting for potential confounders. The cohort had a mean (SD) age of 74.60 (6.61) years for HRS (41.41% male), 81.87 (10.50) years for CLHLS (48.10% male), 72.99 (6.12) years for SHARE (44.27% male), and 73.03 (6.22) years for ELSA (46.59%% male). The prevalence of cognitive frailty was 10.58% for HRS, 6.26% for CLHLS, 12.16% for SHARE, and 5.81% for ELSA. The prevalence of dual sensory impairment was 8.05% for HRS, 3.06% for CLHLS, 10.94% for SHARE, and 4.06% for ELSA. Cox regression revealed a significant synergistic effect between hearing impairment and vision impairment on cognitive frailty risk. Compared to no sensory impairments individuals, those with hearing impairments or vision impairments had a higher risk of cognitive frailty across all cohorts, with individuals with dual sensory impairment exhibiting the highest risk: HRS (Hazard Ratio [HR] = 2.10, 95% CI, 1.71-2.56), CLHLS (HR = 2.08, 95% CI, 1.37-3.15), SHARE (HR = 1.52, 95% CI, 1.35-1.71), and ELSA (HR = 2.77, 95% CI, 1.78-4.31). This study identifies an association between combined hearing and vision impairments and an increased risk of cognitive frailty. These findings suggest that assessing sensory impairments, particularly dual sensory impairment, in older adults may help identify individuals at higher risk of cognitive frailty. Further research, including longitudinal studies and randomized controlled trials, is needed to explore the potential benefits of early sensory interventions for supporting healthy aging.