title: Recurrence of idiopathic sudden sensorineural hearing loss: a retrospective cohort study.
abstract: OBJECTIVE
  To explore the recurrence rate of idiopathic sudden sensorineural hearing loss (ISSNHL).
  
  
  METHODS
  Using 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.
  
  
  RESULTS
  The 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 interval: 1.40-1.81) than did the 0- to 34-year-old age group. Different comorbidities did not significantly affect the incidence of ISSNHL relapse.
  
  
  CONCLUSIONS
  The 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.
  
  
  METHODS
  2B.
authors.affiliation: *Department of Otorhinolaryngology, Chang Gung Memorial Hospital, College of Medicine, Chang Gung University, Linkou, Taoyuan, Taiwan; †Department of Otolaryngology, Chi Mei Medical Center, Tainan City, Taiwan; ‡Department of Medical Research, Chi Mei Medical Center, Tainan City, Taiwan; §Department of Hospital and Health Care Administration, Chia-Nan University of Pharmacy and Science, Tainan City, Taiwan; and ∥Center for General Education, Southern Taiwan University of Science and Technology, Tainan, Taiwan.
authors.forename: Che-Ming
authors.initials: CM
authors.lastname: Wu
authors.forename: Kuan-Ji
authors.initials: KJ
authors.lastname: Lee
authors.forename: Shih-Lun
authors.initials: SL
authors.lastname: Chang
authors.forename: Shih-Feng
authors.initials: SF
authors.lastname: Weng
authors.forename: Yung-Song
authors.initials: YS
authors.lastname: Lin
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D015897:Comorbidity; D016208:Databases, Factual; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis* / Q000453:epidemiology; D003639:Hearing Loss, Sudden / Q000175:diagnosis* / Q000453:epidemiology; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D012008:Recurrence; D012189:Retrospective Studies; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult