A Nationwide Population-Based Study for the Recurrence and Comorbidities in Sudden Sensorineural Hearing Loss

Objectives: The aims of this study were to investigate the cumulative recurrence rate of SSNHL and to determine association between comorbidities and recurrence of SSNHL by comparing patients with and without recurrence. Methods: Using the National Health Insurance Claims Database (NHICD) from 2009 to 2020, we conducted a population-based study. We only enrolled patients whose records showed a prescription for steroid and audiometry findings as well as an appropriate diagnostic code. Recurrence of SSNHL was defined as an episode of SSNHL greater than or equal to 3 months after the first episode of SSNHL. We compared the recurrence rate of SSNHL according to age and number of SSNHL recurrences. We also explored comorbidities including autoimmune, metabolic, chronic renal diseases, cancer, and migraine associated with recurrent SSNHL. Results: A total of 257,123 patients were identified. We found that 6.7% (17,270/257,123) of the patients had at least one recurrence of SSNHL. The recurrence rate increases with the number of recurrences and over time. The incidence per 100,000 people tended to increase with age, and the recurrence rate appeared to decrease with age. We found an increase in the incidence of ankylosing spondylitis (AS) and a decrease in the incidence of type 2 diabetes mellitus (T2DM), myocardial infarction (MI), and hemorrhagic stroke in patients with recurrence. Conclusion: For patients with recurrence or AS, considerable efforts should be made to prevent recurrence. As SSNHL is an emergent otologic condition, when symptoms occur, they should receive immediate treatment. Additional well-designed population-based studies are required to generalize our results. Level of Evidence: 3 Laryngoscope, 134:1417–1425, 2024.