Hearing Intervention for Older Adults With Mild Cognitive Impairment

Importance Hearing loss is a significant modifiable risk factor for cognitive decline, but the effectiveness of hearing intervention for cognition stabilization or improvement still remains controversial. Objective To investigate whether hearing intervention could reduce dementia-level impairment incidence in older adults with coexisting hearing loss and mild cognitive impairment (MCI). Design, Setting, and Participants This multicenter, parallel-group, open-label randomized clinical trial was conducted between September 2021 and February 2024, with the 24-month follow-up completed in February 2026. This study was conducted at 3 tertiary otology outpatient clinics and 3 CHOICE cohort community health stations in Shanghai, China. Of 21 908 adults aged 60 years or older assessed for eligibility, 703 participants with coexisting MCI (Clinical Dementia Rating [CDR] global score of 0.5) and moderate to severe hearing loss were enrolled and randomized. These data were analyzed from February 2026 to July 2026. Interventions Participants were randomized 1:1 to receive either hearing aid intervention (n = 353) or hearing care education (n = 350). Main Outcomes and Measures The primary outcome was the conversion rate from MCI to dementia-level impairment over 24 months, defined as a CDR global score 1 or more. Key prespecified secondary outcomes comprised rate of cognitive improvement (CDR = 0) and CDR global and domain scores. Results Among 703 randomized patients (mean [SD] age, 74.53 [7.16] years; range, 60-96 years; 250 female [35.56%] and 452 male [64.44%]), 610 (86.77%) completed the trial. No significant difference was observed in the primary outcome, in which the conversion rate from MCI to dementia-level impairment was 3.09% (95% CI, 1.62%-5.74%) in the intervention group vs 4.74% (95% CI, 2.60%-8.29%) in the control group (risk difference [RD], −2.07%; 95% CI, −4.74% to 0.61%; relative risk [RR], 0.59; 95% CI, 0.25-1.38; P = .23). Meanwhile, prespecified secondary analysis demonstrated that hearing intervention increased the rate of cognitive improvement (15.34%; 95% CI, 11.84%-19.62% vs 2.36%; 95% CI, 0.99%-5.22%; RD, 12.00%; 95% CI, 8.79%-15.21%; RR, 5.94; 95% CI, 2.46-14.37). No study-related adverse events were reported. Conclusions and Relevance In this study, among older adults with mild cognitive impairment and coexisting hearing loss, a hearing aid intervention did not significantly reduce the incidence of dementia-level impairment at 24 months. Trial Registration Chinese Clinical Trial Registry Identifier: ChiCTR2000036139