A study finds that dementia is more prevalent among older adults who have a moderate or severe hearing loss. The study also found that the prevalence of dementia was much lower among those who used hearing aids.
A study led by researchers at the Johns Hopkins Bloomberg School of Public Health in the US has found that older adults with greater severity of hearing loss were more likely to have dementia, but the likelihood of dementia was lower among hearing aid users compared to non-users.
The analysis in the study covered 2,413 individuals, about half of whom were over 80 and showed a clear association between severity of hearing loss and dementia. The study analysed a nationally representative dataset from the National Health and Aging Trends Study (NHATS) in the US. The NHATS has been ongoing since 2011 and used a sample of American Medicare beneficiaries over age 65.
In the study, 33.5% of the participants had normal hearing, 36.7 % had a mild hearing loss and 29.8% had a moderate to severe hearing loss.
Prevalence of dementia
The prevalence of dementia among the participants in the study with moderate to severe hearing loss was 61% higher than prevalence among participants who had normal hearing. The use of hearing aids was associated with a 32% lower prevalence of dementia in the 853 participants who had moderate to severe hearing loss.
“This study refines what we’ve observed about the link between hearing loss and dementia and builds support for public health action to improve hearing care access,” says lead author Alison Huang, PhD, MPH, senior research associate in the Bloomberg School’s Department of Epidemiology and at the Cochlear Center for Hearing and Public Health, also at the Bloomberg School.
In the study, hearing loss was defined according to better-ear 4-frequency pure tone average, with the following definitions: Normal hearing: < 25 dB; mild hearing loss: 26-40 dB; moderate to severe hearing loss: >40 dB.
Several earlier studies have also shown a relationship between hearing loss and cognitive decline and that the use of hearing aids reduces cognitive decline.
The research letter, “Hearing Loss and Dementia Prevalence in Older Adults in the US”, was published in the journal JAMA.