title: Relative and absolute reliability of functional performance measures for adults with dementia living in residential aged care.
abstract: BACKGROUND
  This pilot investigation aimed to assess the relative and absolute test-retest reliability of commonly used functional performance measures in older adults with dementia residing in residential aged care facilities.
  
  
  METHODS
  A total of 12 participants were tested on the Short Physical Performance Battery (SPPB), the Balance Outcome Measure for Elder Rehab (BOOMER), hand grip strength, anthropometric measures and Bio-electric Impedance Analysis (BIA). This study utilized a seven-day test-retest evaluation. Intra-class Correlation Coefficients (ICC) were used to assess relative reliability, Typical Error of Measurement (TEM) was used to assess the absolute reliability, and Bland-Altman plots were used to assess group and individual levels of agreement.
  
  
  RESULTS
  With the exception of Standing Balance (ICC = 0.49), 2.4-m walk (ICC = 0.68), functional reach (ICC = 0.38), and static timed standing (ICC = 0.47), all measures demonstrated acceptable (>0.71) ICCs. However, only the anthropometric measures demonstrated acceptable levels of absolute reliability (>10% TEM). Bland-Altman analysis showed non-significant (p > 0.05) mean differences, and eight out of the 17 measures showing wide Limits of Agreement (LoA).
  
  
  CONCLUSIONS
  Current measures of functional performance are demonstrably inappropriate for use with a population of older adults with dementia. Authors suggest aligning current measurement strategies with Item Response Theory as a way forward.
authors.affiliation: University of Queensland, School of Nursing and Midwifery, Herston, Queensland, Australia.
authors.forename: Benjamin
authors.identifier: http://orcid.org/0000-0002-8516-7031
authors.initials: B
authors.lastname: Fox
authors.affiliation: University of Queensland, School of Nursing and Midwifery, Herston, Queensland, Australia.|Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Queensland, Australia.
authors.forename: Timothy
authors.initials: T
authors.lastname: Henwood
authors.affiliation: University of Queensland, School of Nursing and Midwifery, Herston, Queensland, Australia.
authors.forename: Christine
authors.initials: C
authors.lastname: Neville
authors.affiliation: Faculty of Health Sciences and Medicine, Bond University, Gold Coast, Queensland, Australia.|Human Potential Centre, AUT University, Auckland, New Zealand.|Cluster for Health Improvement, Faculty of Science, Health, Education and Engineering, University of the Sunshine Coast, Maroochydore, Queensland, Australia.
authors.forename: Justin
authors.initials: J
authors.lastname: Keogh
mesh_terms: D000203:Activities of Daily Living / Q000145:classification / Q000523:psychology; D000369:Aged, 80 and over; D003704:Dementia / Q000175:diagnosis / Q000523:psychology*; D005260:Female; D015577:Geriatric Assessment / Q000379:methods; D006707:Homes for the Aged / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D053580:Muscle Strength; D004856:Postural Balance; D015203:Reproducibility of Results