title: Predictive validity and responsiveness of the functional ambulation category in hemiparetic patients after stroke.
abstract: OBJECTIVE
  To determine the reliability, concurrent and predictive validity, and responsiveness of the Functional Ambulation Category (FAC) in hemiparetic patients after stroke.
  
  
  METHODS
  Prospective cohort.
  
  
  METHODS
  An early rehabilitation center for patients with neurologic disorders.
  
  
  METHODS
  Fifty-five nonambulatory patients after first-ever stroke, with duration of illness between 30 and 60 days, were included.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  FAC, Rivermead Mobility Index (RMI), walking velocity, step length, and six-minute walking test (6MWT) were assessed at the beginning, after 2 and 4 weeks of rehabilitation, and again 6 months later. After 6 months, community ambulation was also assessed. Test-retest and interrater reliability, concurrent, discriminant, and predictive validity and responsiveness of the FAC were calculated.
  
  
  RESULTS
  Based on video examinations, high test-retest reliability (Cohen kappa=.950) and interrater reliability (kappa=.905) were found. FAC scores at the beginning and after 2 weeks, 3 weeks, and 6 months correlated highly with the RMI (Spearman rho=.686, rho=.787, rho=.825, rho=.893, respectively), distance walked in the 6MWT (rho=.949, rho=.937, rho=.931, rho=.906, respectively), walking velocity (rho=.952, rho=.939, rho=.902, rho=.901, respectively), and step length (rho=.952, rho=.932, rho=.896, rho=.877, respectively) at the same time points (all P<.001). The RMI, walking velocity, step length, and distance walked in the 6MWT differed for each FAC category (P<.001). After 4 weeks of rehabilitation, an FAC score of 4 or higher predicted community ambulation at 6 months with 100% sensitivity and 78% specificity. FAC scores changed significantly between the first 2 and second 2 weeks (Wilcoxon z=8.7, z=7.9, respectively; both P<.001) of the inpatient rehabilitation program.
  
  
  CONCLUSIONS
  The FAC has excellent reliability, good concurrent and predictive validity, and good responsiveness in patients with hemiparesis after stroke.
authors.affiliation: Department of Early Neurological Rehabilitation, Klinik Bavaria, Kreischa, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Mehrholz
authors.forename: Katja
authors.initials: K
authors.lastname: Wagner
authors.forename: Katja
authors.initials: K
authors.lastname: Rutte
authors.forename: Daniel
authors.initials: D
authors.lastname: Meissner
authors.forename: Marcus
authors.initials: M
authors.lastname: Pohl
mesh_terms: D005260:Female; D005684:Gait; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D017063:Outcome Assessment, Health Care / Q000379:methods*; D010291:Paresis / Q000209:etiology / Q000503:physiopathology / Q000534:rehabilitation*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012047:Rehabilitation Centers; D012720:Severity of Illness Index; D020521:Stroke / Q000150:complications / Q000503:physiopathology; D000071939:Stroke Rehabilitation; D016138:Walking