An epidemiologic method for assessing the effectiveness of hearing conservation programs using audiometric data.
Adera T; Donahue AM; Malit BD; Gaydos JC
Mil Med 1993 Nov; 158(11):698-701
The effectiveness of a hearing conservation program (HCP) was assessed, using a reference population against which the study population was compared. The study population included 599 workers who received audiometric tests from 1980 through 1989. The criterion for entry into the HCP for these study workers was exposure to the OSHA action level of at least 85 decibels-A (dBA) as an 8 hour time weighted average (TWA). The reference group included 93 workers who had a similar period of follow up, who were exposed to approximately 87dBA as a TWA, and who consistently wore hearing protective devices. Workers in the reference population were generally older than those in the study population. The cumulative incidence of hearing loss was consistently higher for the study than for the reference population in each of five separate age groups. The risk of developing hearing loss as measured by the standard threshold shift was compared between study and reference populations using the risk ratio. The study population demonstrated an increased risk of nearly three fold. Men were twice as likely to develop hearing loss as women. The authors conclude that epidemiologic risk comparison methods, using reference populations, offer an alternative to current methods for HCP evaluation using audiometric data.
NIOSH-Author; Noise-induced-hearing-loss; Noise-exposure; Epidemiology; Risk-factors; Hearing-tests; Audiological-testing; Hearing-protection