Conductive Hearing Loss Associates With Dementia, and Middle Ear Reconstruction Mitigates This Association: A Multinational Database Study.

Objective: To test the hypothesis that conductive hearing loss (CHL) is associated with dementia, and that middle ear reconstruction (MER) associates with improved outcomes for these measures in a multinational electronic health records database.

Study Design: Retrospective cohort study with propensity-score matching (PSM).

Setting: TriNetX is a research database representing about 110 million patients from the United States, Taiwan, Brazil, and India.

Patients: Subjects older than 50 years with no HL and any CHL (ICD-10: H90.0-2). Subjects of any age with and without any MER (CPT: 1010174).

Main Outcome Measures: Odds ratios (ORs) and hazard ratios with 95% confidence intervals (95% CIs) for incident dementia (ICD-10: F01, F03, G30).

Results: Of 103,609 patients older than 50 years experiencing any CHL, 2.74% developed dementia compared with 1.22% of 38,216,019 patients with no HL (OR, 95% CI: 2.29, 2.20-2.37). Of patients experiencing CHL, there were 39,850 who received MER. The average age was 31.3 years, with 51% female patients. A total of 343,876 control patients with CHL were identified; 39,900 patients remained in each cohort after 1:1 PSM for HL- and dementia-related risk factors. Matched risk for developing dementia among MER recipients was 0.33% compared with 0.58% in controls (OR: 0.58, 0.46-0.72).

Conclusions: CHL increases the odds for dementia, and MER improves the odds for incident dementia. This study represents the first population study on the topic of CHL, MER, and dementia.