Unexpected Cognitive Improvement Emerges In Hearing Aid Trial

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In the CHOICE trial, hearing aids were not shown to reduce the 24-month rate of conversion from mild cognitive impairment to dementia. A secondary outcome found cognitive improvement more often among participants assigned to hearing aids, but researchers say the finding needs replication.

Older adults with mild cognitive impairment and moderate-to-severe hearing loss who received hearing aids in the CHOICE trial were more likely to show cognitive improvement over two years than those given hearing care education, researchers reported. The trial did not establish that hearing aids reduced progression to dementia, and its authors said the improvement finding requires confirmation.

The trial’s primary outcome was conversion from mild cognitive impairment to dementia-level impairment, measured using the Clinical Dementia Rating (CDR). Over 24 months, conversion occurred in 3.09% of the hearing aid group and 4.74% of the education group. The estimated relative risk was 0.59, but the difference was not statistically significant (P=0.23).

A prespecified secondary outcome measured improvement from a CDR global score of 0.5 to 0. The researchers reported improvement in 15.34% of hearing aid users, compared with 2.36% of participants in the control group. They calculated a relative risk of 5.94 (P<0.001). That result is a signal from a secondary outcome; it does not establish that hearing aids prevent dementia or reverse cognitive impairment generally.

CHOICE enrolled 703 older adults in Shanghai, with a mean age of 74.5; 64% were men. Participants were randomly assigned to hearing aid intervention (353 people) or hearing care education (350 people). The study took place at three tertiary otology clinics and three community health stations. Hao Wu, MD, PhD, of Shanghai Jiao Tong University School of Medicine, and colleagues reported the findings in JAMA Neurology.

A Signal in a Higher-Risk Group

The results add evidence to a question facing clinicians and older adults: whether treating hearing loss might also affect cognitive outcomes in people already experiencing mild impairment. The higher improvement rate could merit further study, particularly because every participant in CHOICE had mild cognitive impairment at enrollment. It does not change the trial’s primary finding: a reduction in dementia conversion was not demonstrated.

Hearing aids have established benefits for communication and quality of life, independent of any cognitive effect. Wu told MedPage Today that the trial’s improvement result suggests hearing treatment may help some participants regain everyday cognitive and functional capacity. He described that interpretation as a signal requiring confirmation. The findings do not show how much any individual would benefit, or whether the difference would persist beyond the study period.

Earlier Hearing and Cognition Findings

Hearing loss is considered a modifiable dementia risk factor, prompting research into whether hearing treatment can affect cognitive decline. In 2023, the ACHIEVE trial reported no overall treatment effect after three years among cognitively intact older adults. An analysis of a higher-risk subgroup in ACHIEVE found a 48% relative reduction in cognitive change among people who received the hearing intervention.

In an editorial accompanying the CHOICE report, Justin Golub, MD, MS, of Columbia University Irving Medical Center and co-authors said ACHIEVE’s subgroup result offered context for the CHOICE finding. They also called the secondary outcome’s effect size surprisingly large and said it needed replication, especially given the null primary outcome. The two trials involved different populations and outcomes, so their results do not establish a single effect across all older adults.

“The null primary result should be read as ‘not proven,’ rather than ‘no benefit.'”

— Hao Wu, MD, PhD, speaking to MedPage Today

Limits of the Two-Year Results

The primary outcome was underpowered**, according to Wu and colleagues, because dementia conversion over 24 months was substantially less common than they had anticipated. That means the trial could not reliably determine whether hearing aids reduce conversion risk; its nonsignificant result does not prove either that there is no benefit or that a benefit exists.

The authors also cited design limitations. The CDR score threshold used to determine eligibility was not specified in the original protocol or trial registration, which may have introduced selection bias. Using the subjective CDR scale both to screen participants and assess outcomes may also have introduced evaluation bias. The report does not establish whether the secondary finding will hold in other populations, last beyond two years, or translate into changes in daily function for a particular person.