Trajectories of self-reported hearing and their associations with cognition: evidence from the United Kingdom and United States of America.

OBJECTIVE

This study aimed to investigate the relationships between trajectories of change in self-reported hearing over eight years with subsequent effects on cognition, measured using episodic memory.

METHODS

Data were drawn from 5 waves (2008-2016) of the English Longitudinal Study of England (ELSA) and the Health and Retirement Study (HRS), involving 4,875 individuals aged 50+ at the baseline in ELSA and 6,365 in HRS. The latent growth curve modelling was used to identify trajectories of hearing over eight years, and linear regression models were performed to investigate the relationship between hearing trajectory memberships and episodic memory scores, controlling for confounding factors.

RESULTS

Five trajectories of hearing (stable very good, stable fair, poor to fair/good, good to fair, and very good to good) were retained in each study. Individuals whose hearing remains suboptimal and those whose hearing deteriorates within suboptimal levels throughout eight years have significantly poorer episodic memory scores at follow-up than those with stable very good hearing. Conversely, individuals whose hearing declines but is within an optimal category at baseline do not see significantly poorer episodic memory scores than those with consistently optimal hearing. There was no significant relationship between individuals whose hearing improved from suboptimal baseline levels to optimal by follow-up and memory in ELSA. However, analysis using HRS data shows a significant improvement for this trajectory group (-1.260, P < 0.001).

CONCLUSIONS

Either stable fair or deterioration in hearing is associated with worse cognitive function, both stable good or improving hearing is associated with better cognitive function specifically episodic memory.