A Trend in Sudden Sensorineural Hearing Loss: Data from a Population-Based Study.

This is the first study reporting on the incidence and clinical aspects of sudden sensorineural hearing loss (SSNHL) in South Korea. Using Health Insurance Review and Assessment Service data from 2011 to 2015, the monthly incidence of unilateral SSNHL and incidence according to patients' sex, age, and month of diagnosis were investigated. The monthly incidence of unilateral SSNHL increased over the 5-year study period, with a mean annual incidence of 17.76 cases/ 100,000 of the population. The incidence increased with age, with most patients presenting in their 60s. There was a slight female preponderance, with a male-to-female ratio of 1: 1.35. Most new patients were diagnosed in October, and the fewest in January. In conclusion, this large-scale study indicates that unilateral SSNHL has a higher incidence among the elderly, women, and in autumn (i.e., along with colder weather).