Associations Between Hearing Impairment and Mortality Risk in Older Persons: The Blue Mountains Hearing Study

Abstract

To assess whether hearing loss predicts an increased risk of mortality. The Blue Mountains Hearing Study examined 2956 persons (49+ years) during 1997 to 2000. The Australian National Death Index was used to identify deaths until 2005. Hearing loss was defined as the pure-tone average (0.5-4 kHz) of air-conduction hearing thresholds greater than 25 dB HL. Associations between hearing loss and mortality risk were estimated using Cox regression and structural equation modeling (SEM). When we used Cox regression, we discovered that hearing loss was associated with increased risk of cardiovascular (hazard ratio [HR] 1.36, 95% confidence interval [CI] 1.08-1.84) and all-cause (AC) mortality (HR 1.39, 95% CI 1.11-1.79) after adjustment for age and sex but not after multivariable adjustment. SEM pathway analysis, however, revealed a greater AC mortality risk (HR 2.58, 95% CI 1.64-4.05) in persons with hearing loss, which was mediated: cognitive impairment (HR 1.45, 95% CI 1.08-1.94) and walking disability (HR 1.63, 95% CI 1.24-2.15). These variables increased mortality both directly and indirectly through effects on self-rated health. Hearing loss was associated with increased AC mortality via three mediating variables: disability in walking, cognitive impairment, and self-rated health. It is important to recognize that persons with combined disabilities are at increased risk of cardiovascular and AC mortality.