Unexpected Cognitive Improvement Emerges in Hearing Aid Trial

A hearing aid intervention did not reduce dementia incidence among people with mild cognitive impairment and hearing loss in the CHOICE trial, but a secondary outcome suggested that it may have increased the rate of cognitive improvement.

The primary outcome was the conversion rate from mild cognitive impairment to dementia based on Clinical Dementia Rating (CDR) scores, which was 3.09% in the intervention group and 4.74% in the control group. The risk difference was -2.07% and the relative risk (RR) was 0.59 (P=0.23), reported Hao Wu, MD, PhD, of the Shanghai Jiao Tong University School of Medicine in China, and co-authors.

The rate of cognitive improvement, however, was 15.34% in the intervention group and 2.36% in the control group, suggesting a nearly six times greater chance of improvement for people who received hearing aids (RR 5.94, P<0.001), the researchers noted in JAMA Neurology.

“These findings suggest that treating hearing loss may help a meaningful minority of older adults with mild cognitive impairment regain everyday cognitive and functional capacity, and not simply slow decline,” Wu told MedPage Today.

“Because the observed 24-month conversion rate was substantially lower than we anticipated, the primary outcome was underpowered. Therefore, the null primary result should be read as ‘not proven,’ rather than ‘no benefit,'” he added. “Meanwhile, the secondary outcome provided a signal that the rate of cognitive improvement was markedly higher in the intervention group than in the control group.”

Hearing loss is considered a key modifiable risk factor for dementia. In 2023, the ACHIEVE trial — the first study to evaluate a hearing intervention to prevent cognitive decline — reported no overall treatment effect after 3 years among cognitively intact older adults.

In ACHIEVE, an analysis of a high-risk subgroup demonstrated a significant 48% relative reduction in cognitive change for people who received the hearing intervention, observed Justin Golub, MD, MS, of Columbia University Irving Medical Center in New York City, and co-authors in a JAMA Otolaryngology–Head & Neck Surgery editorial.

“ACHIEVE thus substantiates the significant secondary outcome of CHOICE … where all participants had mild cognitive impairment at randomization and were therefore at high risk for cognitive decline,” the editorialists wrote.

The “surprisingly giant effect size” of the secondary outcome in CHOICE requires replication, particularly in light of the null primary outcome finding, but “altogether, these findings suggest that intervention with hearing aids may have an important protective effect for older adults at increased risk of cognitive decline, which is not observed among lower-risk counterparts,” Golub and colleagues noted.

CHOICE was conducted from 2021 to 2026 at three tertiary otology outpatient clinics and three CHOICE cohort community health stations in Shanghai. The study enrolled 703 older adults with moderate-to-severe hearing loss and co-existing mild cognitive impairment, defined as a CDR global score of 0.5.

The sample size was based on preliminary data from a pilot study and published research of dementia conversion rates, which showed that dementia-level impairment developed in 10% of hearing aid users with mild cognitive impairment and 18% of non-users, the researchers said.

CHOICE participants had a mean age of 74.5 years and 64% were men. All were randomized to receive either a hearing aid intervention (353 people) or hearing care education (350 people).

The trial’s primary outcome was the conversion rate from mild cognitive impairment (CDR global score of 0.5) to dementia-level impairment (CDR global score of 1) over 24 months. CDR global scores can range from 0 (normal cognition) to 3 (severe dementia). Prespecified secondary outcomes included the rate of cognitive improvement from a CDR global score of 0.5 to 0.

The study had several limitations, Wu and co-authors acknowledged. The eligibility criterion of a CDR score of 0.5 was not prespecified in the protocol or trial registration, which may have introduced potential selection bias. Relying on the subjective CDR scale for both screening and outcomes also may have introduced evaluation bias.

“Hearing aids have well-established benefits for communication, social engagement, and quality of life, regardless of any effect on cognition,” Wu said. “What CHOICE adds is a signal that, over 2 years and in this population, hearing intervention was associated with a substantially higher rate of cognitive improvement from mild cognitive impairment back to a CDR of 0.”

“This finding is exploratory and needs confirmation, but it indicates that hearing treatment deserves more attention in this population,” he added.