title: The relative and absolute reliability of two balance performance measures in chronic stroke patients.
abstract: OBJECTIVE
  To examine the relative reliability and absolute reliability of the Berg Balance Scale (BBS) and the Postural Assessment Scale for Stroke Patients (PASS) in chronic stroke patients.
  
  
  METHODS
  A total of 52 mild to moderate stroke patients, who had a stroke more than 6 months previously, participated in the study. Both balance measures were administered twice, seven days apart, to the patients. A relative reliability index (intra-class correlation coefficient, ICC2,1) was used to examine the level of agreement between test and retest. Absolute reliability indices, including the Bland and Altman method, the standard error of measurement (SEM), and the smallest real differences (SRD), were used to define the extent to which a balance score varies on test-retest measurements.
  
  
  RESULTS
  Test-retest agreements were high (ICC2,1: BBS = 0.98; PASS = 0.97), indicating excellent agreement from a relative perspective. The SEM of the BBS and PASS, representing the smallest change threshold that indicates a real improvement for a group of individuals, were 2.4 and 1.1, respectively. The SRD of the BBS and PASS were 6.7 and 3.2, respectively, exhibiting the smallest change threshold that indicates a real improvement for a single individual.
  
  
  CONCLUSIONS
  The test-retest agreements of the BBS and PASS were high in mild to moderate chronic stroke patients. The thresholds of both measures to detect real change are acceptable in research and clinical settings.
authors.affiliation: Faculty of Physical Therapy, College of Health Science, Kaohsiung Medical University, Kaohsiung, Taiwan.
authors.forename: Lih-Jiun
authors.initials: LJ
authors.lastname: Liaw
authors.forename: Ching-Lin
authors.initials: CL
authors.lastname: Hsieh
authors.forename: Sing-Kai
authors.initials: SK
authors.lastname: Lo
authors.forename: Hui-Mei
authors.initials: HM
authors.lastname: Chen
authors.forename: Su
authors.initials: S
authors.lastname: Lee
authors.forename: Jau-Hong
authors.initials: JH
authors.lastname: Lin
mesh_terms: D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D004856:Postural Balance; D015203:Reproducibility of Results; D012720:Severity of Illness Index; D020521:Stroke / Q000503:physiopathology*