Evaluation of pure tone audiometry and impedance screening in infant schoolchildren.

STUDY OBJECTIVE The aims were (1) to evaluate impedance measurements against pure tone audiometry as a screening method for the detection of middle ear changes associated with hearing loss in infant school children; (2) to estimate the costs of the health authority of each method. DESIGN The study involved two stage screening in which both methods were offered, pure tone audiometry being carried out by school nurses and impedance screening by a doctor. SETTING 18 infant or primary schools in Langbaurgh, Cleveland, UK. PARTICIPANTS 610 previously unscreened infant school children took part in the study. MEASUREMENTS AND MAIN RESULTS Main outcome measures were the sensitivity, specificity, and predictive value of each screening method, using clinical assessment and action as the validating technique. The sensitivity and the predictive value of a positive test in two stage impedance screening was markedly superior to that of pure tone audiometry. The specificity was similar using the two methods. In addition the impedance methods was more rapid and estimated to consume less resource as a screening procedure than pure tone audiometry. CONCLUSIONS The superiority of the use of impedance screening established in this study should be confirmed in a subsequent audit carried out purely by school nurses.