title: Test-retest reliability and minimal detectable change on balance and ambulation tests, the 36-item short-form health survey, and the unified Parkinson disease rating scale in people with parkinsonism.
abstract: OBJECTIVE
  Distinguishing between a clinically significant change and change due to measurement error can be difficult. The purpose of this study was to determine test-retest reliability and minimal detectable change for the Berg Balance Scale (BBS), forward and backward functional reach, the Romberg Test and the Sharpened Romberg Test (SRT) with eyes open and closed, the Activities-specific Balance Confidence (ABC) Scale, the Six-Minute Walk Test (6MWT), comfortable and fast gait speed, the Timed "Up & Go" Test (TUG), the Medical
  
  
  RESULTS
  Study 36-Item Short-Form Health Survey (SF-36), and the Unified Parkinson Disease Rating Scale (UPDRS) in people with parkinsonism.
  
  
  METHODS
  Thirty-seven community-dwelling adults with parkinsonism (mean age=71 years) participated. The Hoehn and Yahr Scale median score of 2 was on the lower end of the scale; however, the scores ranged from 1 to 4.
  
  
  METHODS
  Subjects were tested twice by the same raters, with 1 week between tests. Test-retest reliability was calculated using intraclass correlation coefficients (ICCs). Minimal detectable change was calculated using a 95% confidence interval (MDC(95)).
  
  
  RESULTS
  The ICCs for test-retest reliability were above .90 for the BBS, ABC Scale, SRT with eyes closed, 6MWT, and comfortable and fast gait speeds. The MDC(95) values for those functional tests were: BBS=5/56, ABC Scale=13%, SRT with eyes closed=19 seconds, 6MWT=82 m, comfortable gait speed=0.18 m/s, and fast gait speed=0.25 m/s. The ICCs for test-retest reliability of SF-36 scores were above .80, with the exception of the social functioning subscale. The MDC(95) values for the SF-36 ranged between 19% and 45%. The MDC(95) values for the UPDRS Activities of Daily Living section, Motor Examination section, and total scores were 4/52, 11/108, and 13/176, respectively.
  
  
  CONCLUSIONS
  Minimal detectable change values are useful to therapists in rehabilitation and wellness programs in determining whether change during or after intervention is clinically significant. High test-retest reliability of scores for the BBS, ABC Scale, SRT with eyes closed, 6MWT, and gait speed make them trustworthy functional assessments in people with parkinsonism. The SF-36 and UPDRS provide quality-of-life and disease severity rating values in the ongoing assessment of people with parkinsonism.
authors: Program in Physical Therapy, Concordia University Wisconsin, Mequon, WI, USA. csteffen1@wi.rr.com
authors: Teresa
authors: T
authors: Steffen
authors: Megan
authors: M
authors: Seney
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D005080:Exercise Test; D005260:Female; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000175:diagnosis / Q000503:physiopathology* / Q000523:psychology; D004856:Postural Balance / Q000502:physiology; D011581:Psychological Tests; D011788:Quality of Life; D015203:Reproducibility of Results; D013647:Task Performance and Analysis; D016138:Walking / Q000502:physiology