title: Reliability of a graded exercise test for assessing recovery from concussion.
abstract: OBJECTIVE
  To evaluate a graded treadmill test for retest reliability (RTR) and interrater reliability (IRR) in the evaluation of the physiologic effects of symptom exacerbation from concussion.
  
  
  METHODS
  Prospective case series (RTR) and blinded rater assessment of 10 actors portraying patients with and without symptom exacerbation (IRR).
  
  
  METHODS
  University Sports Medicine Concussion Clinic.
  
  
  METHODS
  For RTR, 21 refractory concussed patients (11 athletes and 10 nonathletes) and 10 healthy subjects; for IRR, 32 raters representing a variety of health care disciplines.
  
  
  METHODS
  For RTR, a Balke protocol treadmill test to symptom exacerbation before and after 2 to 3 weeks. For IRR, video recordings of actors during the treadmill test viewed by raters blinded to condition.
  
  
  METHODS
  For RTR, agreement of the tests for maximal heart rate (HR), systolic blood pressure, diastolic blood pressure, and rating of perceived exertion. For IRR, presence or absence of symptom exacerbation and the symptom exacerbation HR.
  
  
  RESULTS
  Raters achieved a sensitivity of 99% for identifying actors with symptom exacerbation and a specificity of 89% for ruling out concussion symptoms and agreed on 304 of 320 observations (accuracy of 95%). The intraclass correlation coefficient for the symptom exacerbation HR was large at 0.90 (95% confidence interval, 0.78-0.98). The treadmill test had good RTR for maximum HR (intraclass correlation coefficient, 0.79) but not for systolic blood pressure, diastolic blood pressure, or rating of perceived exertion.
  
  
  CONCLUSIONS
  The Balke exercise treadmill protocol has very good IRR and sufficient RTR for identifying patients with symptom exacerbation from concussion.
authors.affiliation: Department of Orthopaedics and Sports Medicine Institute, University at Buffalo, State University of New York, Buffalo, NY 14214, USA. leddy@buffalo.edu
authors.forename: John J
authors.initials: JJ
authors.lastname: Leddy
authors.forename: John G
authors.initials: JG
authors.lastname: Baker
authors.forename: Karl
authors.initials: K
authors.lastname: Kozlowski
authors.forename: Leslie
authors.initials: L
authors.lastname: Bisson
authors.forename: Barry
authors.initials: B
authors.lastname: Willer
mesh_terms: D000293:Adolescent; D000328:Adult; D056352:Athletes; D001924:Brain Concussion / Q000503:physiopathology / Q000534:rehabilitation*; D005080:Exercise Test / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016544:Patient Simulation; D011446:Prospective Studies; D020127:Recovery of Function / Q000502:physiology*; D015203:Reproducibility of Results; D055815:Young Adult