Late last year, the Lancet retracted a major study that had linked hearing aid use in people with hearing loss to reduced dementia risk.

A coding error had occurred, whereby the data from people with hearing loss who were using hearing aids and those with hearing loss who were not using hearing aids was switched. This led to errors that rendered the findings and conclusions “false and misleading,” the retraction stated.

In fact, those with hearing loss who used hearing aids actually had increased risk of dementia.

At a time when dementia risk tools and guidelines are being updated to include hearing loss as a risk factor, does this change anything?

Professor Kaarin Anstey, director of the UNSW Ageing Futures Institute and lead of the Brain Health and Dementia Centre at NeuRA, says it does not – but it’s important to understand the context.

“There is consistent evidence that people with hearing loss are at increased risk of dementia and this article retraction does not change this,” Professor Anstey explained. “Therefore we still support inclusion of hearing loss in risk assessments.”

“The mechanism for this is unknown. It could be due to third variables, i.e. the factors that cause hearing loss may also cause dementia. Or there may be an increased risk due to lack of sensory stimulation that reduces neuronal connectivity leading to brain atrophy etc. It obviously isn’t possible to do an RCT on this topic,” she continued.

“What remains unclear is the extent to which intervening in people with hearing loss will have a benefit for their future cognitive health. There have been mixed findings on this topic with some studies showing a benefit and some not showing a benefit.”

“A recent RCT led by a world expert Prof Frank Lin found no effect of hearing intervention in reducing cognitive decline in people with hearing loss, but subgroup analysis found that in those at risk of cognitive decline (older, more risk factors, lower education) there was a benefit. But in high functioning adults without risk of cognitive decline, there was no benefit. This is the first published large RCT on this topic – I think that over the next few years we will get more evidence to guide clinical advice on this topic,” Professor Anstey added.

Associate Professor Michael Woodward, who is honorary medical advisor at Dementia Australia and Director of Dementia Research at Austin Health, agreed with this take, adding that it remains important to assess for and treat hearing loss.

“My advice to GPs would be to detect and address hearing loss as it is clearly a risk factor for dementia. And it may be as simple as removing impacted wax – but do not fear hearing aids if needed – indeed, encourage your patients to wear them (older men are particularly notorious for leaving them out),” he said.