A September 24th 2015 article published in the online edition of JAMA-Otolaryngology-Head & Neck Surgery provided data on the relationship between hearing impairment and all-cause mortality.
Lead study author Kevin Contrera, MPH, and MD candidate, along with his colleagues at the Johns Hopkins School of Medicine in Baltimore, combined data from the National Health and Nutrition Examination Survey (NHANES) in order to evaluate the association between hearing impairment and all-cause mortality, which is the rate of death for the population across all causes.
In the study, posted at JAMA’s gated on-line journal, 1,666 adults 70 years of age or older who had received a hearing test were analyzed using NHANES data, which is part of a large, on-going epidemiological study designed to assess the health of the US population using a representative sample.1
Hearing Loss and Mortality: Analyzing the Data
Participants were placed into one of three hearing impaired categories: no hearing loss (n=527), mild hearing loss (n=589) and moderate to more severe (n= 550) and mortality was determined by matching NHANES data and death certificates from the National Death Index through December, 2011.
Interestingly, after adjusting for demographic characteristics and cardiovascular risk factors, their results suggested that moderate or more severe hearing loss was associated with a 39% increased risk of mortality, while a mild hearing loss had a 21% increased risk of mortality, compared to those with normal hearing.
Results of their analysis indicated that individuals with normal hearing were more likely to be younger, female, non-white, non-smokers with no history of cardiovascular disease and stroke.
Previous Studies Support Findings
The results of this study are in good agreement with other recently published findings. For example, in a 2015 prospective observational study of 1,968 adults aged 70 and older who were followed by the researchers for 8 years after the hearing test was completed, Genther and colleagues determined that 42.9% of individuals died compared to 31.4% of individuals with normal hearing on the audiogram.
This study came on the heels of another report by Genther, et al indicating that older people with hearing loss experience a greater incidence and annual rate of hospitalization compared to similarly aged Americans with normal hearing.
Other studies support these findings. In an Icelandic study published in 2014, 4,926 individuals, aged 67 years or older who completed vision and hearing examinations between 2002 and 2006 were followed prospectively for mortality through 2009. Their results indicated that people with hearing loss remained at higher risk for cardiovascular disease, while individuals with both vision and hearing impairment (dual sensory impairment) remained at higher risk of all-cause mortality and cardiovascular disease.
Mortality rates were found to be significantly higher in men with hearing loss alone and with dual sensory impairment.
Finally, a 2010 report from the Blue Mountains Hearing study in Australia, which followed older individuals for a period of 5 to 8 years following a hearing test suggested that hearing loss was associated with increased risk of cardiovascular disease and all-cause mortality after adjustment for age and sex. The researchers analysis, however, revealed a greater all-cause mortality risk in persons with hearing loss, which was mediated by cognitive impairment and walking disability.
Consequences of Untreated Hearing Loss
Clearly, there is a pattern emerging from these studies suggesting that untreated hearing loss leads to significant consequences, including all-cause mortality. Potential explanations for this pattern of results include an interconnected relationship between hearing loss and physical and cognitive functioning that is not completely understood.
Although hearing aids and other rehabilitation methods have as of yet to be proven to reduce morality rates in individuals with significant hearing loss, it is reasonable to assert that hearing care professionals need to take a more active role in the routine hearing screening and follow-up of older adults.
Obviously, the urgency of this situation has been elevated over the past year, as both the Institute of Medicine and the President’s Council of Advisors on Science and Technology (PCAST) have been investigating the public health issue of access and affordability to hearing care as well as the long-term consequences of untreated hearing loss and their mediating factors.
Further Research Needed
In response to request for comment from Hearing News Watch, lead study author Kevin Contrera, MPH, discussed the need for further research to determine if hearing loss necessarily causes death, and the mechanisms behind this potential result.
There needs to be further investigation into whether the treatment of hearing impairment can improve the potential negative impact of hearing loss on health and mortality. Namely, randomized controlled trials would aid in answering the question of whether hearing aids improve survival as well as a number of other health outcomes. -Kevin Contrera, MPH
Mr. Contrera added further, “hearing loss can impact nearly every facet of life–including death. As the population ages, it becomes increasingly important to appropriately identify and treat patients whenever possible.”
- Contrera KJ, Betz J, Genther DJ, Lin FR. Association of Hearing Impairment and Mortality in the National Health and Nutrition Examination Survey. JAMA Otolaryngol Head Neck Surg. Published online September 24, 2015. doi:10.1001/jamaoto.2015.1762