Dementia and hearing aids, again: the ACHIEVE trial
The results of the ACHIEVE trial of hearing interventions aimed at helping cognition in older people are very welcome. This is a really important piece of research and will have implications for patients, clinicians and researchers. As a hearing aid user myself, I am personally very interested in this topic.
The background is that hearing loss from midlife is recognised as a major independent risk factor for developing dementia in later years, so the big question is whether hearing interventions, that is, supporting people to wear hearing aids, help to slow down cognitive decline and prevent dementia. If so, up to 8% of cases of dementia might be prevented, which would be a massive benefit.
There are now quite a few good observational studies showing that people with untreated hearing loss do have an increased risk of cognitive decline and dementia compared to those who wear hearing aids. The problem with these studies is they don’t account for other differences between hearing aid users and non-users, e.g. non-users may have other health and social issues that also contribute to dementia risk. So the only way to address this is by means of a clinical trial that randomly allocates people to active hearing support treatment versus a control condition where they get something else.
The ACHIEVE trial is the first major trial of this kind to report its findings. It included over 900 participants and followed them up for 3 years to measure various aspects of cognition. Interestingly, they were recruited from two different sources. One was simply advertising to the public for eligible volunteers. The other group came from an ongoing study (called ARIC) recruited to study cardiovascular disease in the population. The main finding was that overall there was no difference between the group receiving hearing intervention compared to the controls, who received a health education programme instead. The only difference was seen in the ARIC group, where the intervention group did better than the controls.
Why the difference between the ARIC group and the newly recruited volunteers? The latter were slightly younger, more affluent and in better general health, with fewer other risk factors for dementia (like high blood pressure or diabetes). Thus, maybe people in this group were just at very low risk of developing dementia during the study period and whether they had hearing aids or not made little or no difference to them. In contrast, the ARIC group had several risk factors for dementia and so were more likely to benefit from hearing aids at this stage in their health pathway.
Overall, maybe the results are a little disappointing that there wasn’t a bigger effect for everyone taking part, but they do suggest that supporting people who at higher risk of dementia with interventions like hearing aids. And anyone with hearing loss should bear in mind that wearing hearing aids has many benefits besides potentially reducing your risk of dementia. You can hear better, function better socially, do your work in more comfort, and use the aids as cool Bluetooth devices to stay connected. All of which is great for well-being.