Validation of a questionnaire to identify hearing loss among farm operators

Workers in certain industries (e.g., agriculture) do not participate in a hearing conservation program and rarely receive this important preventive care. The National Institute for Deafness and Communication Disorders (NIDCD) has published a questionnaire to assess a person's need for medical examination of their hearing. The use of a self-administered questionnaire may pose a simple, low cost opportunity to assess the hearing health of workers not included in a hearing conservation program. However, the validity of the NIDCD questionnaire has not been tested. A study was conducted to compare the results of audiometric screening and the NIDCD questionnaire in identifying persons at risk for hearing impairment who may benefit from a medical referral. Data were collected from 103 farm operators at a regional farm show. Receiver-operator characteristic curves, measuring the ability of the questionnaire to correctly classify those with and without the disease suggested that the level of performance of the questionnaire as a whole, ranged from 0.74 to 0.69 (fair to poor). However, selected questionnaire items (e.g., Do you have to strain to understand conversations?) had moderate agreement (0.38 to 0.41) with screening audiogram results. Overall, the 10-item instrument did not perform as well as instruments with fewer items reported in separate studies. These findings suggest that, while less desirable than audiometry, alternative self-administered instruments might perform the better in this group. This approach may be useful as an alternative screening method to detect risk of hearing loss and identifying the need for medical evaluation of hearing sensitivity, particularly among farm operators.