02 August 2024

New dementia report calls for better hearing aid access

Hearing aids should be available to everyone who needs them, according to the latest Lancet Commission analysis of modifiable risk factors for dementia. 

The report suggests that if everyone with hearing loss was treated, monitored and appropriately managed, dementia's prevalence in the population would be reduced by 7%.

Hearing loss remains top of the researchers' list of modifiable risk factors, which has risen from 12 to 14 with two additions this year - vision loss and high LDL cholesterol.

The suggestion is that addressing hearing loss and keeping people socially engaged is a cost-effective and beneficial health policy approach to the rising incidence of dementia in the population.

The report also calls for a "decrease in harmful noise exposure to reduce hearing loss".

The commission has carried out five new meta-analyses on the links between hearing loss and subsequent dementia since it last reported in 2020, all of which found strong associations. The researchers also discovered that the risk of cognitive decline increased with hearing loss severity by 16% with every 10 dB average threshold deterioration.

"The evidence that treating hearing loss decreases the risk of dementia is now stronger than when our previous commission report was published," say the authors. "Use of hearing aids appears to be particularly effective in people with hearing loss and additional risk factors for dementia."

The studies all included objective measures of hearing through pure-tone audiometry, more than five years of follow-up, adjustment for age, cardiovascular factors, and cognitive ability or education at baseline, and a risk for the outcome of incident dementia.

Global estimates suggest that 20% of people live with hearing loss, including common hearing problems that hearing aids could address. About 60% of them are older than 50.

The report's lead author, UCL's Professor Gill Livingston, said: "Our new report reveals that there is much more that can and should be done to reduce the risk of dementia. It's never too early or too late to take action, with opportunities to make an impact at any stage of life."

The commission of 27 dementia experts calls for governments to be ambitious about tackling risks factors for dementia, arguing that addressing these throughout life could prevent or delay nearly half of dementia cases.

The report acknowledges that some of its recommendations assume a causal relationship between the risk factors and dementia, which may only be true in some cases.

Another significant risk factor for dementia is social isolation, which experts have long acknowledged is a consequence of untreated hearing loss. The report notes that psychosocial factors such as social isolation might be a mechanism to explain how hearing loss might increase dementia risk.

Randomised control trials give the best evidence for causal relationships. However, they are ethically problematic because they require treatments that are proven to be beneficial to be withheld from the control group.

More than 900,000 people are estimated to be living with dementia in the UK, and by 2040 this figure is expected to rise to 1.4 million.