Hearing Loss as a Modifier of the Association Between Comorbidities and Mortality.

BACKGROUND: Comorbidities increase mortality risk in older adults. Hearing loss impacts health care communication, utilization, and outcomes may influence this association, but to our knowledge, no study to-date has examined the impact of hearing loss on the comorbidity-mortality relationship. METHODS: Data from the national health and nutrition examination survey 2009-2010 cycle was linked with mortality data from the national death index through 2020. In individuals ≥ 70 years with data for pure tone air conduction audiometry, we used cox proportional hazards model to evaluate the association between hearing, comorbidity count and mortality. RESULTS: During an median follow-up of 9.3 years, 46% (398/874) individuals died. The 65% (571/874) of participants had hearing loss, of whom 27% used hearing aids. Hearing loss was associated with increased mortality, and risk was even higher in those with multiple comorbidities and hearing loss. After adjustment for sex, age, marital status, and smoking history, both hearing loss and comorbidity remained important predictors of mortality. Risk of mortality increased independently with hearing loss (aHR = 1.4 95% CI = 1.0-2.0 and with high vs. low comorbidity count ≥ 3 vs. < 3; aHR = 1.7 95% CI = 0.9-3.1), with the highest mortality risk among those with both ≥ 3 comorbidities and hearing loss (aHR = 2.3, 95% CI = 1.7-3.2; p value for interaction = 0.03). CONCLUSIONS: In this nationally representative sample of US adults over the age of 70 years, audiometric hearing loss modified the association between comorbidity and mortality. Additional research is needed to investigate whether treating age-related hearing loss could improve survival among older adults with and without comorbidities.