Association of Hearing Loss With Hospitalization and Burden of Disease in Older Adults

To the Editor: Hearing loss (HL) is a chronic condition that affects nearly 2 of every 3 adults aged 70 years or older in the United States.¹ Hearing loss has broader implications for older adults, being independently associated with poorer cognitive² and physical functioning.³

The association of HL with other health economic outcomes, such as health care use, is unstudied. We investigated the association of HL with hospitalization and burden of disease in a nationally representative study of adults aged 70 years or older.

We analyzed combined data from the 2005-2006 and 2009-2010 cycles of the National Health and Nutrition Examination Survey (NHANES), an ongoing epidemiological study designed to assess the health and functional status of the civilian, noninstitutionalized US population.⁴ Air-conduction pure-tone audiometry was administered to all individuals aged 70 years or older, according to established NHANES protocols.

Hearing was defined per the World Health Organization⁵ as the average of hearing thresholds (in decibels) at speech frequencies (0.5-4 kHz) in the better-hearing ear (range: 0-100 dB). Data on hospitalizations (during the previous 12 months) and on burden of disease (during the previous 30 days) were gathered through computer-assisted or interviewer-administered questionnaires. Hospitalization was defined as any hospitalization (yes or no) and number of hospitalizations (0, 1, or >1 times). Burden of disease was defined as self-reported number of days of poor physical health, poor mental health, and inactivity due to health (0-10 or >10 days).⁴

Data were analyzed using stepwise multivariable logistic and ordinal logistic regression models to investigate the association of HL as a continuous variable (per 25 dB) with hospitalization and burden of disease, adjusting for demographic characteristics and cardiovascular risk factors. We accounted for the complex sampling design using sample weights according to National Center for Health Statistics guidelines.

Data were analyzed using Stata version 11 (StataCorp). A 2-sided threshold of P < .05 was used to evaluate statistical significance. The NHANES protocol was reviewed and approved by the National Center for Health Statistic's institutional review board and informed written consent was obtained from all participants.

Compared with individuals with normal hearing (n = 529), individuals with HL (n = 1140) were more likely to be older (mean age: 74.7 vs 77.0 years; P <.001), male, white, less educated, in lower income households, have a positive history for cardiovascular risk factors, have a history of hospitalization in the past year (18.7% vs 23.8%; P = .02), and have more hospitalizations (1.27 [95% CI, 1.13-1.41] vs 1.52 [95% CI, 1.40-1.64]; P = .03) (Table 1).

Fully adjusted models accounting for demographic and cardiovascular risk factors demonstrated that HL (per 25 dB) was significantly associated with any hospitalization (odds ratio [OR], 1.32 [95% CI, 1.07-1.63]), number of hospitalizations (OR, 1.35 [95% CI, 1.09-1.68]), more than 10 days of self-reported poor physical health (OR, 1.36 [95% CI, 1.06-1.74]), and more than 10 days of self-reported poor mental health (OR, 1.57 [95% CI, 1.20-2.06]) (Table 2). Hearing loss was not associated with days of self-reported inactivity due to health.

For adults aged 70 years or older, HL was independently associated with hospitalization and poorer self-reported health over the past 12 months. This is, to our knowledge, the first nationally representative study to demonstrate that HL is independently associated with increased health care use and burden of disease among older adults. Pathways through which HL would contribute to the odds of hospitalization and poorer self-reported health include effects of HL on social isolation,⁶ health-related oral literacy, and cognitive decline.²

Alternatively, residual confounding by unmeasured factors not accounted for in our analyses (eg, subclinical microvascular disease) could also underlie the observed associations. A principal limitation of this cross-sectional study is that we cannot determine the temporal course and mechanisms through which hearing loss could be associated with hospitalization and burden of disease.

Future economic analyses may need to take into account these potential broader implications of HL on the health and functioning of older adults. Additional research is needed to investigate the basis of these observed associations and whether hearing rehabilitative therapies could help reduce hospitalizations and improve self-reported health in older adults with HL.

Author Contributions: Drs Genther and Lin had full access to all of the data in the study and take responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design: Genther, Frick, Chen, Lin.

Acquisition of data: Genther, Chen.

Analysis and interpretation of data: Genther, Frick, Betz, Lin

Drafting of the manuscript: Genther, Lin.

Critical revision of the manuscript for important intellectual content: Genther, Frick, Chen, Betz, Lin.

Statistical analysis: Genther, Frick, Chen, Betz, Lin.

Obtained funding: Lin.

Administrative, technical, or material support: Chen, Lin.

Study supervision: Lin.

Funding/Support: This study was supported by grant T32DC000027-24 from the National Institutes of Health and grant 1K23DC011279 from the National Institute on Deafness and Other Communication Disorders, with further funding from the Triological Society and the American College of Surgeons through a clinician scientist award, and funding from the Eleanor Schwartz Charitable Foundation. Funding for National Health and Nutrition Examination Survey data collection was provided by the Centers for Disease Control and Prevention, National Center for Health Statistics, and the National Institute of Deafness and Other Communication Disorders (for audiometric data).

Role of the Sponsor: The sponsors had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; and preparation, review, or approval of the manuscript; and decision to submit the manuscript for publication.