Hearing loss increasing among adolescents

Shargorodsky J. JAMA. 2010; 304:772-778.

The prevalence of hearing loss among adolescents aged 12 to 19 years rose 31% between 1988 and 2006, according to recent study data.

As a common sensory disorder with serious ramifications for children, researchers from several institutions opted to examine how hearing loss in this population has changed during the past few years.

“In school-aged children, even slight hearing loss (>15-24 dB) can create a need for speech therapy, auditory training, and special accommodations,” wrote the researchers. “Mild hearing loss in young children can impair speech and language development and lead to decreased educational achievement and impaired social-emotional development.”

The researchers noted that adolescent hearing loss is poorly understood so they targeted children aged 12 to 19 years.

Results derived from a cross-sectional analysis comparing data from the Third National Health and Nutrition Survey (NHANES III), which includes information collected during 1988 to 1994, with reports from NHANES 2005-2006.

For both time periods, trained technicians used audiometers and a modified Hughson Westlake procedure to assess study participants’ hearing thresholds. Low-frequency and high-frequency hearing loss were also measured, with each also being characterized as unilateral or bilateral.

The researchers said 1,771 adolescents qualified for analysis, with no significant differences between the two survey periods for age, race/ethnicity, sex or poverty-income ratio, although the chances of an adolescent having a history of at least three ear infections appeared greater in NHANES III.

Results indicated that the prevalence of any hearing loss among adolescents aged 12 to 19 years was 14.9% (95% CI, 13-16.9) during 1988 to 1994, with this proportion rising to 19.5% (95% CI, 15.2-23.8) during 2005 to 2006.

Unilateral hearing loss was also higher during NHANES III, according to the researchers, with the number growing from 11.1% (95% CI, 9.5-12.8) during 1988 to 1994 to 14% (95% CI, 10.4-17.6) during 2005 to 2006. Bilateral hearing loss also increased from 3.8% (95% CI, 2.6-4.9) to 5.5% (95% CI, 3.9-7.1) by NHANES 2005-2006.

Data from both NHANES studies demonstrated higher prevalence of high-frequency hearing loss compared to low-frequency hearing loss. High-frequency loss, however, was more common in the adolescent group.

Slight hearing loss and mild or worse hearing loss occurred more frequently among adolescents during NHANES 2005-2006 when compared with NHANES III.

The researchers noted that factors such as age or race/ethnicity in either survey did not affect risk of hearing loss. Girls, however, were less likely than boys to display hearing loss in both studies.

During 2005 to 2006, poverty-income ratio was significantly linked to a higher risk of hearing loss, with an adjusted OR of 1.6 (95% CI, 1.1-2.32) for families living below the poverty threshold when compared with those living above it.

Although this study shows that prevalence of hearing loss is increasing among adolescents, the researchers pointed out that more studies on potential risk factors still need to be conducted to hinder the development of hearing loss.