# Hearing loss and cognitive function among older adults in 18 high-income countries: Moderating and Mediating factors

## TL;DR

This study finds that hearing loss is linked to worse cognitive performance in older adults, with effects varying by gender and education, and suggests that psychosocial factors like loneliness may play a role.

## Contribution

The study explores moderating and mediating factors of hearing loss on cognitive function across 18 high-income countries using a novel machine learning approach.

## Key findings

- Hearing loss is significantly associated with poorer cognitive performance in memory, verbal fluency, and other domains.
- The negative effects of hearing loss on cognition vary by gender, education, and age group.
- Feelings of isolation, loneliness, and depression partially explain the cognitive decline linked to hearing loss.

## Abstract

Hearing loss is a major, potentially modifiable risk factor for cognitive impairment, but its moderating and mediating factors remain underexplored in cross-national settings.

We used the data from a cross-national survey, the Survey of Health, Ageing and Retirement in Europe (SHARE). 38,506 participants aged 65 and above across 17 European countries and Israel from SHARE wave 6 were included. The study applied the Double Machine Learning (DML) approach to evaluate the association of hearing aid use with cognitive function in older adults, and to test demographic moderators and psychosocial mediators.

Hearing loss was significantly associated with poorer cognitive performance in temporal orientation (coefficient = −0.061; 95% CI: [−0.076, −0.045]), memory (–0.448; 95% CI: −0.520, −0.375]), numeracy (–0.061; 95% CI: [−0.092, −0.030]), and verbal fluency (–0.379; 95% CI: [−0.529, −0.229]). The associations varied by gender, education and age group, such as stronger associations with verbal fluency of women, and memory of higher educated individuals. Mediation analyses indicated that the negative associations of hearing loss with cognitive function may be partially explained by increased feelings of isolation, loneliness and depression.

This study highlights the cognitive burden of hearing loss in later life and underscores the importance of early detection and intervention. Addressing psychosocial consequences of hearing impairment may help mitigate its impact on cognitive health. Further longitudinal research is needed to validate these findings and clarify causal pathways.