Prevalence of Hearing Aid Use Among Older Adults in the United States

To the Editor

Hearing loss is highly prevalent in older adults and has been found to be associated with incident dementia¹, falls ^{2, 3}, and cognitive functioning ⁴. These associations may be mediated through a causal pathway¹, but the role of hearing aids and other forms of rehabilitative interventions in possibly mitigating these effects remains unknown. In order to understand the scope of current hearing loss treatment and the extent to which hearing loss remains untreated in the United States, we estimated the overall prevalence of hearing aid use among U.S adults ≥ 50 years with audiometric hearing loss using a nationally-representative dataset.

Methods

We analyzed data from the 1999–2006 cycles of the National Health and Nutritional Examination Surveys (NHANES), an ongoing epidemiological survey designed to assess the health and functional status of the civilian, non-institutionalized U.S. population⁵. Hearing aid use was assessed with an interviewer-administered questionnaire and was based on whether an individual reported wearing a hearing aid at least once a day (1999–2004) or for at least 5 hours per week (2005–6). Air-conduction pure tone audiometry was administered to a half sample of all participants 50–69 years from 1999–2004 (n=1888), and all participants ≥ 70 years from 2005–6 (n=717). Audiometry was performed in a sound-attenuating booth according to established NHANES protocols. A speech frequency pure-tone average (average of hearing thresholds at 0.5, 1, 2, and 4 kHz) of greater than 25 dB hearing level (HL) in both ears was defined as hearing loss per World Health Organization criteria⁶, and this is the level at which hearing loss begins to impair communication in daily life. U.S. population counts were estimated using the midpoint of population totals in each cycle and averaged across combined cycles when appropriate. We accounted for the complex sampling design in all analyses by using sample weights according to National Center for Health Statistics (NCHS) guidelines.

Results

We estimate that 3.8 million or 14.2% of Americans ≥ 50 years with hearing loss from 1999–2006 wear hearing aids (Table). The prevalence of hearing aid use is consistently low (<4%) in individuals with mild hearing loss across all age decades but generally increases with older age in individuals with moderate or greater hearing loss. Overall, the prevalence of hearing aid use in individuals with hearing loss ≥ 25 dB increases with every age decade from 4.3% in individuals 50–59 years to 22.1% in individuals ≥ 80 years. There are an estimated 22.9 million older Americans with audiometric hearing loss who do not use hearing aids.

Table.

Prevalence and number of individuals ≥ 50 years with hearing loss^a using hearing aids in the United States, NHANES 1999–2006

	Prevalence of Hearing Aid Use Among Adults with Hearing Lossa > 25dB % (95% CI)b
	Sex		Hearing loss severityc		Total
Age, years	Male	Female	Mild (>25 – 40 dB)	Moderate or Greater >40dB	Overall Prevalence of Hearing Aid Use	Number with Hearing Aids, millions	Number with Hearing Lossa >25dB, millions
50–59	4.3 (0–9.5)	4.5 (0–13.5)	2.7 (0–6.6)	11.8 (0–27.5)	4.3 (0–8.8)	0.20	4.5
60–69	7.3 (2.5–12.1)	7.2 (1.4–13.0)	2.6 (0–5.2)	23.9 (10.6–37.2)	7.3 (3.6–10.9)	0.44	6.1
70–79	21.1 (14.5–27.6)	12.7 (6.0–19.5)	3.4 (0.3–6.5)	47.8 (37.0–58.6)	17.0 (12.4–21.6)	1.5	8.8
80+	28.1 (20.3–35.9)	17.9 (11.2–24.7)	3.4 (0–7.7)	35.7 (28.7–42.7)	22.1 (18.5–25.8)	1.6	7.3
Estimated Total Number of Individuals with Hearing Aids and with Hearing Loss, respectively, in millions					3.8c		26.7

^aHearing loss defined as a speech-frequency pure tone average (PTA) of hearing thresholds at 0.5, 1, 2, and 4 kHz tones presented by air-conduction in the better hearing ear of >25 dB.

^bAll values represent percent prevalence unless otherwise noted.

^cNumbers do not sum to group total because of rounding.

Comment

For individuals 50 years and older in the U.S. with hearing loss, one in seven individuals uses hearing aids, and for working-age adults (50–59 years) the rate of hearing aid use declines to less than one in twenty. These are the first national estimates of hearing aid prevalence in the U.S. population based on audiometric data and a large, well-characterized representative sample. Previous estimates have ranged between 10–20% and have been based on population-based cohorts^{7, 8} or industry-supported marketing surveys that are not representative of the U.S. population. The low observed rate of hearing aid use in the U.S is likely multifactorial in etiology and related to a general perception of hearing loss as an inconsequential part of the aging process, the absence of health insurance reimbursement for hearing rehabilitative services, and the lack of research on the impact of hearing loss treatment. Only one moderately-sized randomized controlled trial of hearing aids has ever been conducted examining the broader impact of hearing aids, and this study did show positive effects of hearing aids on cognition and other functional domains ⁹. Recent research demonstrating strong associations between hearing loss and domains critical to aging (dementia¹, cognitive functioning ⁴, and falls ^{2, 3}) highlights the need for further intervention studies to determine the possible role of hearing rehabilitative modalities in helping mitigate these adverse outcomes. If these studies demonstrate even a small beneficial effect of hearing aid use, these findings would have significant implications for public health given that hearing aids are readily available and currently not utilized by nearly 23 million older adults with hearing loss.