Association Between Cochlear Implants and Dementia in Severe-to-Profound Hearing Loss Patients: Results From the National Insurance Service Survey 2010-2020.

Objective: This study aims to investigate whether restoring hearing through a cochlear implant (CI) influences the risk of dementia development, using data obtained from the South Korea's National Health Information Database.

Study design: A longitudinal follow-up study.

Setting: Data from the Korean National Health Insurance Service.

Patients and intervention: This study examines the association between CIs and dementia in patients with severe-to-profound hearing loss. Data were collected from January 2010 to December 2020. All eligible patients were confirmed to have no previous diagnosis of dementia at the time of their hearing loss diagnosis. A total of 356,850 patients 50 years and older were included, with 2,447 having had Cis implanted and 354,403 who had not.

Main outcome measures: Patients who had CIs were compared with those who did not, focusing on the newly diagnosed dementia.

Results: Among the CI recipients, 274 (11.2%) were newly diagnosed with dementia, compared with 61,939 (17.5%) among the nonrecipients. This difference was statistically significant (p < 0.001). For patients 70 years and older, a similar level of significance was observed. The interval between the diagnosis of the hearing loss and the subsequent development of dementia was significantly associated with the use of CIs (587.7 versus 1886.9 d, p < 0.001).

Conclusions: The study elucidated the association between CIs and reduced dementia in patients with severe-to-profound hearing loss using nationwide data in South Korea. CIs are beneficial in preventing dementia, even in patients older than 70 years.