Hearing intervention versus health education control to reduce cognitive decline in older adults with hearing loss in the USA (ACHIEVE): a multicentre, randomised controlled trial
Comprehensive Overview
Published in The Lancet in 2023, this study, known as the ACHIEVE trial, asked whether treating hearing loss with hearing aids and audiological support could slow cognitive decline in older adults, since hearing loss is one of the largest modifiable risk factors for dementia, yet no large randomized trial had directly tested whether correcting it protects thinking and memory. Researchers conducted a three-year, multicenter randomized trial at four US sites, enrolling 977 adults aged 70 to 84 with untreated hearing loss but without significant cognitive impairment, drawn from two groups: 238 older adults already at elevated cardiovascular and cognitive risk from a long-running heart-health study, and 739 healthier community volunteers. Participants were randomly assigned to a hearing intervention of fitted hearing aids plus ongoing counseling, or a control program of general health education on chronic disease prevention, and researchers tracked changes in a comprehensive measure of global cognitive function annually over three years. The topline result was that, across the full combined group, the hearing intervention did not significantly reduce three-year cognitive decline compared with the control, though a prespecified analysis revealed the treatment's effect differed meaningfully depending on which of the two participant groups a person belonged to.
Outcomes and Implications
The single most important finding was that although the hearing intervention showed no overall benefit across the full study group, a prespecified sensitivity analysis found the treatment's effect differed significantly between the two participant populations, and among the higher-risk group of older adults drawn from a longstanding cardiovascular health study, the hearing intervention was associated with a 48% reduction in three-year cognitive decline compared with health education. Among the healthier, younger, and more highly educated volunteers who made up the larger de novo group, the hearing intervention produced no measurable cognitive benefit, even though these participants used their hearing aids just as consistently and showed equally strong improvement in everyday communication as the higher-risk group. This pattern suggests that a healthy volunteer effect, in which people who enroll in studies tend to be unusually healthy to begin with, combined with a much slower rate of natural cognitive decline in the de novo group, may have simply left little room for any intervention to show a detectable effect over just three years. No meaningful safety differences emerged between the two study arms. The authors conclude that hearing intervention may meaningfully slow cognitive decline specifically in older adults already at heightened risk, supporting hearing loss as a modifiable target for dementia-prevention strategies in this population, while cautioning that longer follow-up is needed to determine whether benefits eventually emerge in lower-risk individuals as well.