This study investigated progressive hearing loss in a cohort of children who were identified with permanent mild bilateral hearing loss.
This population-based study included 207 children with permanent mild bilateral hearing loss, diagnosed and followed from 2003 to 2016 in 1 region of Canada. Clinical characteristics and initial audiologic results were collected prospectively at diagnosis, and audiologic information was updated. Changes in hearing levels between the 1st and most recent assessment were analyzed to determine progressive hearing loss. Clinical characteristics were compared between children with progressive and stable hearing loss. The association between risk indicators and progressive hearing loss was explored through logistic regression.
A total of 47.4% (94 of 207) had progressive hearing loss in at least 1 ear, and 50% (47 of 94) of those experienced more than 20-dB average drop in thresholds. For these 94 children, a total of 147 ears were affected, and 116 (78.9%) ears experienced sufficient change in thresholds to be coded as a worse category of hearing loss. In the subset of 85 children with more than 5 years of audiologic follow-up, 56.4% (53/85) showed a decrease in hearing. Of the total sample of 207 children, 137 (66.2%) continued to have mild hearing loss in the better ear. There was no association between the risk factors examined (family history of hearing loss, admission to the neonatal intensive care unit, or presence of a syndrome) and progressive hearing loss.
This study found that almost half of children with mild bilateral hearing loss showed a decrease in hearing in at least 1 ear. One third of the children first diagnosed with mild hearing loss in the better ear now have moderate or worse hearing loss in both ears. These findings point to the importance of careful long-term monitoring of children who present with mild hearing loss.
Senior Scientist, CHEO Research Institute