Aging and Hearing Loss: Data-Driven Studies for Consumers and Audiologists

For years, our field and industry have been bandying around rule-of-thumb statistics, chief among them that somewhere between 25-50% of people 65 and over have hearing loss that is sufficient to interfere with normal communication.  Who knows where that statistic came from? It’s a heuristic that’s gained the mantel of truth over time.  And the stated range of 25 to 50%, was too broad to be of much use except by a few practitioners who brandished it to scare people into buying hearing aids.

Such was the situation in 2011 when Dr Frank Lin and colleagues at Johns Hopkins summarized the situation in a seminal paper on prevalence of hearing loss in US Seniors:

“Hearing loss has been associated with cognitive and functional decline in older adults and may be amenable to rehabilitative interventions, but national estimates of hearing loss prevalence and hearing aid use in older adults are unavailable.” (Lin et al. 2011)

 

Johns Hopkins Starts an Avalanche

A plethora of studies with real, verifiable statistics began to emerge in 2011 as part of national epidemiological studies of health and aging.  Lin et al (2011) set off the avalanche by accessing and analyzing National Health and Nutritional Examination Survey (NHANES) data, which measured hearing for the first time in 2005/6, when 717 seniors were scrutinized in terms of their audiometric thresholds and hearing histories (e.g., noise exposure, hearing aid use). 

Taken together with other study data on subjects’ medical histories and demographics, our field received its first report out from the Lin Research Group at Johns Hopkins on the true prevalence of hearing loss and hearing aid use in different groups of seniors (see Table 1).  The research was especially important to hearing practitioners and their patients because the statistics were “generalizable to the U.S.population.” 

Findings were also of special importance to our field and to consumers because the researchers distinguished hearing decreases from hearing loss. Hearing can decrease without creating enough “loss” to create communication problems, so it makes sense to only call it a hearing loss/impairment if it causes communication difficulty.  Lin et al (2011) categorized their subjects according to the World Health Organization’s  (WHO) definition that people have a hearing impairment only when their hearing thresholds drop to the  point that it “…affects their ability to hear human speech.”  When thresholds hit that point, it is a “mild” hearing loss; greater drops produce “moderate” or greater hearing loss.

Table 1.  Hearing Loss (defined in terms of hearing impairment) and Hearing Aid Use in US senior populations.

There are lots of rich data in this and subsequent studies.  As expected, men have more hearing loss than women. Other findings are shown in Table 1.  Perhaps because the cut-off age for seniors is 70 instead of the traditional 65, the results show more hearing loss in seniors than that old “25-50%” range indicated.  Unexpected was the finding that hearing loss is more common in older whites than in blacks.  It will be interesting to find out as further research is done whether this reflects a “protective” genetic pattern or is due to environment exposure differences between the two groups.

Laments 

The 2011 Lin et al study found low treatment rates for seniors with hearing loss sufficient to cause problems with speech understanding.  Fewer than half of seniors with moderate hearing loss wore hearing aids.  Only 3.4% of those with mild hearing loss did.  This is lamentable but not unexpected.

 “…only a minority of older people with these impairments use hearing aids …There’s a general perception that hearing loss in older adults is not very important.”  (FR Lin, NYTimes)

Here’s another lament.  The connection between uncorrected hearing loss and mental health appears strong and devastating.  Those who cannot maintain good communication due to hearing loss tend to withdraw, lose social connections, experience depression, and have poorer health than those who “treat” their hearing loss and maintain good communication via hearing aids.

Here’s a further lament. There are strong neuroscientific arguments for age effects on auditory and cognitive processing, though not for the scare tactics we’re seeing in some current hearing aid advertising. In the long run, as research is compiled linking hearing aid use to daily function, it’s not unlikely that the the “use it or lose it” mantra of the gym will have applications to auditory and cognitive functions as well. In the meantime, as research delves into these areas, those who address their hearing losses with amplification when their hearing losses are mild may be nipping impairment in the bud and maintaining functionality.

Paths of Actions for Consumers and Providers 

Laments aside, there are things that can be done now.  There is ongoing research to guide present-day decision-making.  Smart patients with a strong drive to maintain communication and connectivity are likely to do something about perceived hearing problems. What they do is likely to be guided by their access to data and study conclusions.  To the extent that these assumptions hold up, audiologists are encouraged to think of active seniors as people who are:

• getting more empowered to handle their hearing difficulties,
• accessing research to gain informed opinions on what actions are in their best interests, and 
• communicating their viewpoint by their actions as well as word-of mouth to friends, associates, and hearing healthcare providers.

In support of those views, next week’s post provides a lengthy compilation of salient research from 2011 to the present, accompanied by the investigators’ conclusions.