Hearing aid initiation and risk of cognitive decline and dementia

 

In older adults with hearing impairment, receiving a new hearing aid prescription was associated with lower 7-year dementia risk, but
differences in overall cognition were modest and equivocal.

 

Gap.
Hearing loss is a suspected dementia risk factor, but long-term evidence for
effectiveness of hearing aids for neurocognitive health is limited.
Research question.
Does hearing aid prescription and hearing aid use influence overall cognition or
dementia risk over 7 years in older adults with hearing impairment?

 

Design &
observational data
Emulated two target trials using data from the ASPREE
study and nested ALSOP cohort
Eligibility criteria
Dementia-free, aged 70+, self-reported hearing problems,
no past hearing aid use
Treatment
strategies
i) Use hearing aids and do not use hearing aids
ii) Use hearing aids never, rarely/sometimes, often/always
Follow-up
Approximately 7 years from when new hearing aid
prescriptions were first self-reported
Outcomes
Overall cognition score (confirmatory factor analysis) and
diagnosed dementia (DSM-IV criteria)
Causal contrast
i) Effect of new hearing aid prescription*
ii) Effect of initiating given frequency of hearing aid use*
Estimation
Multiple imputation for missing data. Effects estimated
using parametric g-formula
* Total effect for time to event outcome (dementia);1 partly survival conditional effect for cognition2

 

2777 included (mean age 75 years, 48% female), of whom 664 received a new hearing
aid prescription by time zero.
Minimal differences in estimated mean overall cognition score.
Dose-dependently lower estimated dementia risk.

 

Hearing aids may dose-dependently reduce dementia risk.
We estimated that hearing aid prescription reduced 7-year dementia risk by 33% in
older people with hearing loss, with benefit proportional to use frequency.
Little benefit was found for the overall cognition score, though there was greater
benefit in high-risk subgroups (like in ACHIEVE trial).3