Hearing impairment increases economic inequality.

Objective We evaluated the change in income level in a hearing-impaired population. Methods The study subjects were selected from the Korean National Health Insurance Service-Health Screening Cohort data from 2002-2015 of Koreans ≥ 40 years old. In all, 5,857 hearing-impaired subjects were matched with 23,428 comparison participants. The difference in the initial income level and the income level at 1, 2, 3, 4, and 5 years post-enrollment were compared between the hearing-impaired and comparison groups. The interaction of time*hearing impairment/comparison was estimated. Results Both the hearing-impaired group and the comparison group showed increased income levels over time. In the hearing-impaired group, the income levels at 4 and 5 years post-enrollment were higher than the initial income level (each p < 0.001). In the comparison group, the income levels of all the participants after 1-5 years were higher than the initial income level (each p < 0.001). The interaction of time*hearing impairment was statistically significant (p = 0.021). Conclusion The increase in income over time was relatively lower in the hearing-impaired adult population; therefore, the gap in income level widened between this population and the normal-hearing population.