title: The Minimal Clinically Important Difference in Vestibular Schwannoma Quality-of-Life Assessment: An Important Step beyond P < .05.
abstract: OBJECTIVE
  Several studies have demonstrated small but statistically significant differences in quality-of-life (QOL) scores among vestibular schwannoma (VS) treatment modalities. However, does a several-point difference on a 100-point scale really matter? The minimal clinically important difference (MCID)-defined as the smallest difference in scores that patients perceive as important and that could lead to a change in management-was developed to answer this important question. While the MCID has been determined for QOL measures used in other diseases, it remains undefined in the VS literature.
  
  
  METHODS
  Distribution- and anchor-based techniques were utilized to define the MCID for the Penn Acoustic Neuroma Quality of Life (PANQOL) and 36-Item Short Form Health Survey (SF-36).
  
  
  METHODS
  Two academic referral centers.
  
  
  METHODS
  Patients with VS (N = 538).
  
  
  METHODS
  Cross-sectional postal survey.
  
  
  METHODS
  MCID for PANQOL domains and total score and SF-36 Physical and Mental Health Component Summary scores.
  
  
  RESULTS
  The MCID (median, interquartile range) for the PANQOL total score was 11 points (10-12); the MCIDs for individual domains were as follows: hearing, 6 (5-8); balance, 16 (14-19); facial, 10 (no interquartile range); pain, 11 (10-13); energy, 13 (10-17); anxiety, 11 (5-22); and general, 15 (11-19). The MCID was 7 points (6-11) for the SF-36 Mental Health Component Summary score and 8 points (6-10) for the Physical Health Component Summary score.
  
  
  CONCLUSIONS
  The MCIDs determined in the current study generally exceed differences reported in previous prospective studies, in which conclusions about QOL benefit (or harm) among VS treatment modalities were based on statistical significance alone. Moving forward, these MCIDs should be considered when interpreting results of VS QOL studies.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Mayo Clinic School of Medicine, Rochester, Minnesota, USA carlson.matthew@mayo.edu.
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Carlson
authors.affiliation: Department of Neurosurgery, Bergen University Hospital, Bergen, Norway.
authors.forename: Øystein Vesterli
authors.initials: ØV
authors.lastname: Tveiten
authors.affiliation: Department of Epidemiology, Mayo Clinic School of Medicine, Rochester, Minnesota, USA.
authors.forename: Kathleen J
authors.initials: KJ
authors.lastname: Yost
authors.affiliation: Department of Health Sciences Research, Biomedical Statistics and Informatics, Mayo Clinic School of Medicine, Rochester, Minnesota, USA.
authors.forename: Christine M
authors.initials: CM
authors.lastname: Lohse
authors.affiliation: Department of Neurosurgery, Bergen University Hospital, Bergen, Norway Institute of Surgical Sciences, University of Bergen, Bergen, Norway.
authors.forename: Morten
authors.initials: M
authors.lastname: Lund-Johansen
authors.affiliation: Department of Neurologic Surgery, Mayo Clinic School of Medicine, Rochester, Minnesota, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Link
mesh_terms: D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009464:Neuroma, Acoustic / Q000523:psychology*; D011788:Quality of Life
keywords: acoustic neuroma; cerebellopontine angle; gamma knife radiosurgery; microsurgery; minimal clinically important difference; patient-reported outcome measures; quality of life; stereotactic radiosurgery; vestibular schwannoma