title: Different Patterns of Hearing Loss among Tinnitus Patients: A Latent Class Analysis of a Large Sample.
abstract: BACKGROUND
  The heterogeneity of tinnitus is a major challenge for tinnitus research. Even if a complex interaction of many factors is involved in the etiology of tinnitus, hearing loss (HL) has been identified as the most relevant etiologic factor. Here, we used a data-driven approach to identify patterns of hearing function in a large sample of tinnitus patients presenting in a tinnitus clinic.
  
  
  METHODS
  Data from 2,838 patients presenting at the Tinnitus Center of the University Regensburg between 2007 and 2014 have been analyzed. Standard audiometric data were frequency-wise categorized in four categories [a: normal hearing (0-20 dB HL); b: moderate HL (25-50 dB HL; representing outer hair cell loss); c: severe HL (>50 dB HL; representing outer and inner hair cell loss); d: no data available] and entered in a latent class analysis, a statistical method to find subtypes of cases in multivariate categorical data. To validate the clinical relevance of the identified latent classes, they were compared with respect to clinical and demographic characteristics of their members.
  
  
  RESULTS
  The classification algorithm identified eight distinct latent classes with an excellent separation. Patient classes differed with respect to demographic (e.g., age, gender) and clinical characteristics (e.g., tinnitus location, tinnitus severity, gradual, or abrupt onset, etc.).
  
  
  CONCLUSIONS
  Our results demonstrate that data-driven categorization of hearing function seems to be a promising approach for profiling tinnitus patients, as it revealed distinct subtypes that reflect prototypic forms of HL and that differ in several relevant clinical characteristics.
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany; Interdisciplinary Tinnitus Center of the University of Regensburg, Regensburg, Germany.
authors.forename: Berthold
authors.initials: B
authors.lastname: Langguth
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany; kbo Lech-Mangfall-Klinik Agatharied, Hausham, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Landgrebe
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany; Interdisciplinary Tinnitus Center of the University of Regensburg, Regensburg, Germany.
authors.forename: Winfried
authors.initials: W
authors.lastname: Schlee
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany; Interdisciplinary Tinnitus Center of the University of Regensburg, Regensburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Schecklmann
authors.affiliation: Interdisciplinary Tinnitus Center of the University of Regensburg, Regensburg, Germany; Department of Otorhinolaryngology, University of Regensburg, Regensburg, Germany.
authors.forename: Veronika
authors.initials: V
authors.lastname: Vielsmeier
authors.affiliation: Interdisciplinary Tinnitus Center of the University of Regensburg, Regensburg, Germany; Department of Otorhinolaryngology, University of Regensburg, Regensburg, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Steffens
authors.affiliation: Interdisciplinary Tinnitus Center of the University of Regensburg , Regensburg , Germany.
authors.forename: Susanne
authors.initials: S
authors.lastname: Staudinger
authors.affiliation: Department of Statistical Science, University College London , London , UK.
authors.forename: Hannah
authors.initials: H
authors.lastname: Frick
authors.affiliation: Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany; HSD University of Applied Sciences, Cologne, Germany.
authors.forename: Ulrich
authors.initials: U
authors.lastname: Frick
keywords: audiometry; chronic tinnitus; cluster analysis; hearing loss; latent classes