# The validity of visual and hearing impairment in predicting dementia and cognitive impairment in older adults: a systematic review and meta-analysis

## TL;DR

This study finds that visual and hearing impairments in older adults are linked to higher risks of dementia and cognitive decline, suggesting early screening could help reduce these risks.

## Contribution

This is the first systematic review and meta-analysis to quantify the association between sensory impairments and dementia/cognitive impairment in older adults.

## Key findings

- Dual sensory impairment is strongly associated with dementia (OR 1.66) and cognitive impairment (OR 2.08).
- Visual and hearing impairments independently increase dementia and cognitive impairment risks.
- Healthcare professionals should screen older adults with sensory impairments to mitigate dementia risk.

## Abstract

The number of people with dementia and cognitive impairment is rising every year as the older population grows. The higher prevalence and mortality rates of dementia and cognitive impairment place an enormous burden on healthcare and economic systems worldwide. Studies have shown that older adults with sensory impairments are at a higher risk of developing dementia and cognitive impairment than normal older adults. There is a lack of systematic reviews on the relationship between sensory impairment and dementia and cognitive impairment in older persons. This meta-analysis aimed to analyze the correlation of visual impairment, hearing impairment, and dual sensory impairment with dementia and cognitive impairment, and to provide guidance for reducing the incidence of dementia and cognitive impairment in older adults.

Computerized searches were conducted using the CNKI, Wanfang, Vip, Sinomed, PubMed, Web of Science, Cochrane Library, and Embase databases. Supplementary searches were performed on 2 clinical trial registries.

Meta-analysis was performed by log-transforming the study-specific estimates. The heterogeneity of studies was characterized by Q-test and I2. The results of the studies indicated that dual sensory impairment was associated with dementia [OR 95% CI 1.66 (1.47, 1.86)], visual impairment was associated with dementia [OR 95% CI 1.60 (1.48, 1.74)], hearing impairment was associated with dementia [OR 95% CI 1.26 (1.22, 1.31)], dual sensory impairment was associated with cognitive impairment [OR 95% CI 2.08 (1.70, 2.54)], visual impairment was associated with cognitive impairment [OR 95% CI 1.84 (1.44, 2.36)], and hearing impairment was associated with cognitive impairment in old age [OR 95% CI 1.50 (1.36, 1.65)].

Sensory impairment is a predictor of dementia and cognitive impairment. Healthcare professionals should prioritize screening older adults with sensory impairments to reduce the incidence of dementia and cognitive impairment.

https://www.crd.york.ac.uk/prospero/, identifier CRD42024606342.