Education, occupation, noise exposure history and the 10-yr cumulative incidence of hearing impairment in older adults

The purpose of this study was to determine the 10-yr cumulative incidence of hearing impairment and associations of education, occupation and noise exposure history with the incidence of hearing impairment in a population-based cohort study of 3753 adults ages 48-92 yr at the baseline examinations during 1993-1995 in Beaver Dam, WI. Hearing thresholds were measured at baseline, 2.5 yr-, 5 yr-, and 10-yr follow-up examinations. Hearing impairment was defined as a pure-tone average (PTA) > 25 dB HL at 500, 1000, 2000, and 4000 Hz. Demographic characteristics and occupational histories were obtained by questionnaire. The 10-yr cumulative incidence of hearing impairment was 37.2%. Age (5 yr; Hazard Ratio (HR) = 1.81), sex (M vs W; HR = 2.29), occupation based on longest held job (production/operations/farming vs others; HR = 1.34), marital status (unmarried vs married; HR = 1.29) and education (<16 vs 16 + yr; HR = 1.40) were associated with the 10 yr incidence. History of noisy jobs was not associated with the 10-yr incidence of hearing impairment. The risk of hearing impairment was high, with women experiencing a slightly later onset. Markers of socioeconomic status were associated with hearing impairment, suggesting that hearing impairment in older adults may be associated with modifiable lifestyle and environmental factors, and therefore, at least partially preventable. (C) 2009 Elsevier B.V. All rights reserved.