Hearing loss as a risk factor for agricultural injuries.

BACKGROUND: Previous studies suggested that hearing impairment based on self-report might increase the risk of agricultural injuries. However, self-reported hearing measures may be subject to inaccuracy and subjective perception. We assessed the association of agricultural injuries with hearing loss and other hearing characteristics using measured hearing. METHODS: Study subjects were 150 farmers who participated in the Iowa Certified Safe Farm study. Injury information was collected by telephone interviews at 2-5 month intervals from September 1999 to October 2002. Hearing levels were measured annually using the pure tone audiometry from 1998 to 2002. Adjusted rate ratios of injuries were calculated using the multivariate Poisson regression model. RESULTS: Hearing loss in the better ear (RR = 1.62), hearing asymmetry (RR = 1.67), and fair/poor self-reported hearing (RR = 1.96) were significantly associated with the risk of agricultural injuries. It is notable that self-reported hearing might be a stronger predictor of injuries than pure tone audiometry (PTA). Exposure to noise elevated the risk of injuries in those farmers with hearing loss or hearing asymmetry. The occasional use of hearing protection was significantly associated with agricultural injuries. CONCLUSIONS: This study adds substantial evidence that hearing loss acts as a risk for agricultural injuries. Prevention of hearing loss and noise exposure may be important in reducing the burden of agricultural injuries.

A comparison of self-reported hearing and pure tone threshold average in the Iowa Farm Family Health and Hazard Survey.

BACKGROUND: Self-reported hearing measures are useful for surveying hearing loss in a population because they are short, and easy to administer by either questionnaire or telephone. This study aims to assess the performance of several self-reported hearing measures to identify hearing loss in a group of Iowa farmers. METHODS: The study subjects were 98 male farmers who participated in the Iowa Farm Family Health and Hazard Survey. We tested three self-reported hearing measures; the hearing screening questions, the Rating Scale for Each Ear (RSEE), and the Health, Education and Welfare-Expanded Hearing Ability Scale (HEW-EHAS), which were originally developed and implemented in the National Health Interview Survey. The sensitivity and specificity of the self-reported hearing measures were assessed by comparing them with pure tone threshold averages. These sensitivity and specificity measures were compared between younger and older age groups. RESULTS: The sensitivities of the screening questions, RSEE, and HEW-EHAS were 73.0%, 66.7%, and 53.3%, respectively. The specificities of the self-reported hearing measures were similar, which ranged from 81.4% to 84.8%. The sensitivities of the self-reported hearing measures were higher in the younger age group while the specificities were higher in the older age group. CONCLUSIONS: The results of this study support the use of simple screening questions in identifying hearing loss among farmers.