Roughly 20% of 12- to 19-year-olds in the United States have some form of hearing loss, up from 15% of adolescents surveyed between 1988 and 1994, a study has shown.
That represents a significant 31% jump that is likely underestimated, according to Dr. Josef Shargorodsky of the Brigham and Women's Hospital in Boston and his associates.
Dr. Shargorodsky, who is also of the Massachusetts Eye and Ear Infirmary, Boston, and his associates looked at data from the National Health and Nutrition Examination Survey (NHANES) 2005-2006 and compared them with data from NHANES III, conducted between 1988 and 1994. Both surveys provide nationally representative data on U.S. civilians aged 12-19 years, and both surveys included audiometry testing of both high- and low-frequency hearing (JAMA 2010;304:772-8).
A total of 2,928 NHANES III participants who had full data from a complete audiometry exam were included for analysis in the more recent study; there were 1,771 participants from NHANES 2005-2006 who had complete data.
There were no differences between the groups in terms of age, race, sex, or poverty-income ratio, although NHANES III participants were more likely to have had a history of three or more ear infections.
Dr. Shargorodsky and his associates found that among NHANES III participants, surveyed between 1988 and 1994, the prevalence of any hearing loss greater than 15 dB among 12- to 19-year-olds was 15%. By the 2005-2006 survey, in contrast, that number had jumped to 20%, representing roughly 6.5 million individuals.
The increases persisted when the data were stratified by type of hearing loss. For example, 11% of NHANES III participants had unilateral hearing loss; by 2005-2006, that number had jumped to 14%. The same increase was repeated when looking only at bilateral hearing loss, with a prevalence of 4% during NHANES III and 5.5% in 2005-2006.
The investigators also found that high-frequency hearing loss (13% in 1988-1994, vs. 16% in 2005-2006) was more prevalent than low-frequency loss (6% in 1988-1994, vs. 9% in 2005-2006) in both time periods.
However, only the change in high-frequency loss was significant.
Even more significant—and more troubling—was the increased prevalence of mild or worse hearing loss (25 dB or greater) in the 2005-2006 survey (as opposed to “slight” hearing loss of between 15 and 25 dB). That figure jumped from 3.5% to 5%—or more than 1 in 20 adolescents.
Dr. Shargorodsky and his associates pointed out some limitations to their study. For one, they wrote, “children whose hearing aids could not be removed, who could not tolerate earphones, or who had cochlear implants were not tested,” although this likely contributed to underestimation of hearing loss, if anything.
Additionally, the study's cross-sectional design could not assess causality.
“Interval factors between surveys, such as vaccination against Haemophilus influenzae and Streptococcus pneumoniae, as well as greater awareness of music-induced hearing loss, may have led to the expectation of no change or a reduction in the prevalence of hearing loss, but this was not observed,” the researchers said.
Dr. Shargorodsky and his associates reported having no disclosures relevant to this study, which was funded by the Massachusetts Eye and Ear Infirmary Foundation and the Vanderbilt University.
Roughly 20% of U.S. teens have some form of hearing loss.
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