title: Interpreting change on the SCAT3 in professional ice hockey players.
abstract: OBJECTIVE
  To examine test-retest reliability of the SCAT3 for two consecutive seasons using a large sample of professional male ice hockey players, and to make recommendations for interpreting change on the test.
  
  
  METHODS
  A cross-sectional descriptive study.
  
  
  METHODS
  Preseason baseline testing was administered in the beginning of the seasons 2013-2014 and 2014-2015 to 179 professional male hockey players in rink side settings.
  
  
  RESULTS
  The test-retest reliabilities of the SCAT3 components were uniformly low. However, the majority of athletes remained grossly within their own individual performance range when two pre-season SCAT3 baseline scores were compared to published normative reference values. Being tested by the same person or a different person did not influence the results. It was uncommon for the Symptom score to worsen by ≥3 points, the Symptom Severity score to worsen by ≥5 points, SAC total score to worsen by ≥3 points, M-BESS total error points to increase by ≥3, or the time to complete Tandem Gait to increase by ≥4s; each occurred in less than 10% of the sample.
  
  
  CONCLUSIONS
  The SCAT3 has low test-retest reliability. Change scores should be interpreted with caution, and more research is needed to determine the clinical usefulness of the SCAT3 for diagnosing concussion and monitoring recovery. Careful examination of the natural distributions of difference scores provides clinicians with useful information on how to interpret change on the test.
authors.affiliation: UKK Institute for Health Promotion Research, Tampere Research Centre of Sports Medicine, Finland. Electronic address: timo.hanninen@fimnet.fi.
authors.forename: Timo
authors.initials: T
authors.lastname: Hänninen
authors.affiliation: UKK Institute for Health Promotion Research, Tampere Research Centre of Sports Medicine, Finland.
authors.forename: Jari
authors.initials: J
authors.lastname: Parkkari
authors.affiliation: International Ice Hockey Federation (IIHF), Switzerland; Liiga/Finnish Ice Hockey Association, Finland; Medisport Ltd., Finland.
authors.forename: Markku
authors.initials: M
authors.lastname: Tuominen
authors.affiliation: Department of Physical Medicine and Rehabilitation, Harvard Medical School, Spaulding Rehabilitation Hospital, USA; MassGeneral Hospital for Children Sport Concussion Program, USA; Home Base, A Red Sox Foundation and Massachusetts General Hospital Program, USA.
authors.forename: Grant L
authors.initials: GL
authors.lastname: Iverson
authors.affiliation: Department of Neurosurgery, Tampere University Hospital, Finland.
authors.forename: Juha
authors.initials: J
authors.lastname: Öhman
authors.affiliation: Institute of Behavioural Sciences, Division of Cognitive Psychology and Neuropsychology, University of Helsinki, Finland.
authors.forename: Matti
authors.initials: M
authors.lastname: Vartiainen
authors.affiliation: Department of Neurosurgery, Tampere University Hospital, Finland.
authors.forename: Teemu M
authors.initials: TM
authors.lastname: Luoto
mesh_terms: D000293:Adolescent; D000328:Adult; D001924:Brain Concussion / Q000175:diagnosis*; D003430:Cross-Sectional Studies; D006688:Hockey / Q000293:injuries*; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests / Q000592:standards*; D012016:Reference Values; D015203:Reproducibility of Results; D015599:Trauma Severity Indices; D055815:Young Adult
keywords: Baseline survey; Brain concussion; Head injuries; Ice hockey