Predictors of hearing loss in school entrants in a developing country

Background: Hearing loss is a prevalent and significant disability that impairs functional development and educational attainment of school children in developing countries. Lack of a simple and practical screening protocol often deters routine and systematic hearing screening at school entry.
Aim: To identify predictors of hearing loss for a practical screening model in school-aged children.
Settings and Design: Community-based, retrospective case-control study of school entrants in an inner city.
Methods: Results from the audiologic and non-audiologic examination of 50 hearing impaired children in randomly selected mainstream schools were compared with those of a control group of 150 normal hearing children, matched for age and sex from the same population. The non-audiologic evaluation consisted of medical history, general physical examination, anthropometry, motor skills, intelligence and visual acuity while the audiologic assessment consisted of otoscopy, audiometry and tympanometry.
Statistical Analysis: Multiple logistic regression analysis of significant variables derived from univariate analysis incorporating student t-test and chi-square.
Results: Besides parental literacy (OR:0.3; 95% CI:0.16-0.68), non-audiologic variables showed no association with hearing loss. In contrast, most audiologic indicators, enlarged nasal turbinate (OR:3.3; 95% CI:0.98-11.31), debris or foreign bodies in the ear canal (OR:5.4; 95% CI:1.0-36.03), impacted cerumen (OR:6.2; 95% CI:2.12-14.33), dull tympanic membrane (OR:2.2; 95% CI:1.10-4.46), perforated ear drum (OR:24.3; 95% CI:2.93-1100.17) and otitis media with effusion OME (OR:14.2; 95% CI:6.22-33.09), were associated with hearing loss. However, only parental literacy (OR:0.3; 95% CI:0.16-0.69), impacted cerumen (OR:4.0; 95% CI:1.66-9.43) and OME (OR:11.0; 95% CI:4.74-25.62) emerged as predictors.
Conclusion: Selective screening based on the identification of impacted cerumen and OME will facilitate the detection of a significant proportion of hearing impaired school entrants.

Keywords
School screening, hearing loss, risk factors, impacted cerumen, otitis media