Recurrence of Idiopathic Sudden Sensorineural Hearing Loss: A Retrospective Cohort Study

OBJECTIVETo explore the recurrence rate of idiopathic sudden sensorineural hearing loss (ISSNHL). DESIGNUsing the Taiwan Longitudinal Health Insurance Database, we compared in a retrospective cohort study 45,715 patients with ISSNHL between January 2001 and December 2006 with 45,715 age-, gender-, and comorbidity-matched controls without ISSNHL. We followed each patient from 180 days after the initial diagnosis until the end of 2009 and evaluated the incidence of ISSNHL for 3 years minimum. RESULTSThe cumulative incidence of ISSNHL recurrence was 4.99%. Cox proportional hazard regressions showed that the 50- to 64-year-old age group had a higher adjusted hazard ratio (1.59; 95% confidence interval1.40–1.81) than did the 0- to 34-year-old age group. Different comorbidities did not significantly affect the incidence of ISSNHL relapse. CONCLUSIONSThe risk of an ISSNHL relapse in patients with a history of ISSNHL was higher than was the risk of a first occurrence of ISSNHL in the Controls. We suggest that physicians counsel patients with a history of ISSNHL to seek medical attention if they have hearing impairments because they may also have a high risk of an ISSNHL relapse.Evidence Level2B