Over-70s at high risk of cognitive impairment and dementia stand to benefit the most from hearing aid intervention, US researchers report in a landmark trial.

They found that use of hearing aids for over three years was associated with a 48% reduction in the rate of cognitive decline in high-risk adults but not among otherwise-healthy patients with a low dementia risk.

Lead author Professor Frank Lin, from John Hopkins University, said results from the first-of-its-kind randomised trial provided “compelling evidence” for targeting hearing loss in dementia prevention.

The researchers assigned 977 patients (mean age 77) with adult-onset bilateral hearing loss but no substantial cognitive impairment to receive hearing aids or a health education program, which acted as a control.