Hearing Aids & Cognitive Decline

The Lancet has just published the results of the first randomized and controlled trial evaluating the effect of hearing aids on cognitive decline and dementia when given to older adults with hearing loss. A substantial body of evidence suggests that hearing loss, which is quite common among older adults, is associated with a greater risk for both cognitive decline and dementia. Additionally, a systematic review of observational studies published in JAMA Neurology earlier this year indicates that the use of hearing restoration devices mitigates some of this risk. However, until now no interventional trials have yet been conducted.

Titled the ACHIEVE (Aging and Cognitive Health Evaluation in Elders) study, 2 separate cohorts of adults aged 70-84 were randomized (but unblinded) to receive either audiologist-supplied hearing aids or an evidence-based program taught by a certified health educator. They were evaluated with a variety of cognition-based exams annually over a 3-year period. 

Although overall no effect of hearing aids was observed, the results were quite encouraging. When analysis was restricted to one of the cohorts, participants in ARIC (Atherosclerosis Risk in Communities), had a 48% reduction in cognitive decline over the 3-year period when given hearing aids. This cohort was considered to be at higher risk for decline compared to the second cohort (which was younger, had higher education levels, fewer cardiovascular risk factors, etc.). The rate of decline in ARIC was greater, perhaps allowing for an effect to be observed within only a 3-year period. This study clearly shows benefits for those at high risk of decline, and it remains possible that a benefit exists even for those not considered high-risk, but 3 years may not be enough time to detect it.