A survey of hearing loss in Vancouver school children. I. Methodology and prevalence.

"TkESPITE the fact that chemotherapy has en*-* abled control of purulent otitis media and its sequelae,1 except perhaps in the lower social classes,2 hearing loss remains an important con¬ temporary problem in child health. The National Health Survey3 revealed that 15% of impairments in children under 15 years were due to hearing loss. From 3 to 5% of school children are found on screening to have hearing impair¬ ment sufficient to warrant further study or treat¬ ment,4 and 1.5 to 3% of school children may have a hearing defect requiring special medical and educational help.5 During recent years, serous or secretory otitis media (sterile fluid in the middle ear) has been recognized to an increasing degree as a cause of mild conductive hearing loss.6 Although the etiology, pathogenesis and natural history of this disorder require clarification, there is evidence that non-function or poor function of the Eustachian tube is associated with an accumulation of fluid in the middle ear.7 Carter8 found fluid in the middle ear in 92 out of 100 consecutive children with conductive hearing loss of 20 decibels (db) or more. Armstrong9 reported that secretory otitis media is the most common cause of hearing loss in children, and that four-fifths of these patients are under 8 years of age. Even slight degrees of residual deafness of about 15 db are likely to lead to backwardness in such basic subjects as English and arithmetic.10 Ac¬ cordingly, the early identification of children with school failure and the clarification of the causal factors are a major concern of the school health service.