An increasing prevalence of hearing impairment and associated risk factors over three decades of the Alameda County Study

Objectives. This study assessed changes in the prevalence of hearing impairment in persons aged 50 years and older over the past 30 years and identified risk factors. Methods. Age-adjusted hearing impairment prevalence rates at four time intervals were calculated from the Alameda County Study (n = 5108). Logistic regression models analyzed risk factors from 1974 for 1994 incident hearing impairment. Results. The prevalence of hearing impairment nearly doubled between 1965 and 1994. The increase was significantly greater for men. The higher incidence was associated with potentially high-noise-exposure occupations for men and with symptoms and conditions associated with ototoxic drug use for both men and women. Exercise was protective. Conclusions. Given the serious health and social consequences of hearing impairment, its increasing prevalence is cause for concern.