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

Objective 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. Methods 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. Results Meta-analysis was performed by log-transforming the study-specific estimates. The heterogeneity of studies was characterized by Q-test and I 2 . 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)]. Conclusion 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. Systematic review registration https://www.crd.york.ac.uk/prospero/ , identifier CRD42024606342.