The Modifying Role of Hearing Aids in Delaying the Onset of Alzheimer’s, Depression, Alcohol Disorder, and Risk of Falling Among Adults with Hearing Loss

Motivation. More than 27 million Americans 50 years or older suffer from hearing loss (HL). It reduces social interaction, precipitously lowers quality of life, and has been linked to severe cognitive and health decline. Hearing aids (HA) may prevent or mitigate the onset of conditions associated with mental and physical decline.

Objective. This novel study longitudinally followed patients 50 years of age and older who had not been diagnosed with Alzheimer’s disease or dementia (AD), anxiety or depression, drug or alcohol disorder, and injuries associated with falling 12 months prior to their index HL diagnosis to estimate the association between HA use and risk of development of these conditions within three years of HL diagnosis.

Data. We performed a retrospective cohort study of adults with HL using a national, private insurance claims database Clinformatics® Data Mart Database. This claims database captures all healthcare encounters for 79 million adults and children. The study period covered 2008 to 2016. To infer patients with new HL diagnosis, we excluded patients with a HL diagnosis or a HAs procedure codes within one year prior to the index HL diagnosis. Patients with pre-existing diagnosis of any of our outcome conditions were also excluded.

Study Design. We conducted bivariate analyses of baseline demographic characteristics and comorbid conditions at the time of HL diagnosis for HA users and non-users. To examine disease-free survival of HA users versus non-users, we constructed Kaplan-Meier product-limit survival curves for each of our outcomes. We applied Log-Rank tests to examine the proportional hazards assumption and to test for differences in survival curves. Finally, we developed Cox proportional hazards regression models to calculate unadjusted and risk adjusted hazard ratios to measure the effect of HA use on each of our four outcomes within 3 years of HL. All models adjusted for age, sex, race/ethnicity, U.S. Census geographic divisions, and clinically relevant morbidities.

Principal Findings. Among 176,716 adults aged 50 and older diagnosed with HL, 22,799 (13%) used HAs. Large gender and racial/ethnic gaps exist in HA use. Approximately, 11.3% of female vs. 14.5% of male patients used HAs (P < 0.0001); furthermore, 14.1% of White vs. 9.5% of Black (P < 0.0001) and 7.8% of Hispanic patients (P < 0.0001) used HAs. At the state-level, Pearson correlation coefficient indicates negative associations between incidence rate of HA use and AD (r=-0.294; p=0.034). The risk-adjusted hazard ratios of being diagnosed with AD, depression or anxiety, drug or alcohol disorder, and injuries associated with falling within 3 years after HL diagnosis, for those who used HA vs. those who did not, were respectively lower by 0.82 (95% CI: 0.76-0.88), 0.92 (95% CI: 0.89-0.95), 0.91 (95% CI:0.80-1.04), and 0.86 (95% CI: 0.81-0.92).

Policy Implications and Conclusions. Our study demonstrates the modifiable role of HA in delaying the onset or prevention of devastating and high resource intense conditions of cognitive and health decline. This is important because HL is increasingly common among older adults and early use of HA may prevent or delay physical and mental decline.