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 to 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 clincal 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 method 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.