Increased Risk of Dementia Following a Diagnosis of Hearing Impairment: A South Korean Nationwide Cohort Study

Abstract

Background: Among the older adults, hearing impairment is a common problem and may contribute to dementia. Objective: Therefore, we aimed to examine the association between hearing impairment and the risk of dementia among older adults in South Korea. Methods: Using the Korean National Health Insurance Service-Senior Cohort from 2005 to 2019, we collected data of 44,728 patients. Hearing impairment was determined using the national disability registry. Propensity score matching (1:1) was performed to match patients with and without hearing impairment (case: 22,364, control: 22,364). A Cox proportional hazards regression model was built to analyze the association between hearing impairment and dementia. Results: Patients with hearing impairment had a higher risk of dementia than those without hearing impairment (hazard ratio [HR] = 1.28, 95% confidence interval [CI] = 1.23–1.34). Assessing the degree of disability, both severe (HR = 1.25, 95% CI = 1.16–1.35) and mild conditions (HR = 1.29, 95% CI = 1.23–1.35) had an increased risk of dementia, respectively. Conclusions: Older patients with hearing impairment exhibit an increased risk of dementia, thereby warranting a new approach to dementia care among these patients regardless of the degree of hearing impairment.