title: Clinimetric properties of the de Morton Mobility Index in healthy, community-dwelling older adults.
abstract: OBJECTIVE
  To investigate the clinimetric properties of the de Morton Mobility Index (DEMMI) in healthy, community-dwelling older adults.
  
  
  METHODS
  Cohort study.
  
  
  METHODS
  Retirement village and Returned and Services League (RSL) club in Melbourne, Australia.
  
  
  METHODS
  All participants were 65 years or older, healthy, and living within the community. The validation study included participants recruited from a retirement village (n=61), and the reliability studies included participants recruited from an RSL club and a subset of participants from the retirement village.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Mobility was assessed using the DEMMI. The percentage of participants who scored the highest and lowest possible score on the DEMMI was calculated to determine whether a floor or ceiling effect occurred. The minimal clinically important difference (MCID) was estimated using a distribution-based method. Reliability was assessed independently and concurrently using the minimal detectable change at 90% confidence (MDC₉₀).
  
  
  RESULTS
  Evidence of convergent and discriminant validity was obtained for the DEMMI by examining correlations with measures of related constructs, the Lower Extremity Functional Scale (r=.69) and Quality of Life Scale scores (r=.28), respectively. Participants who ambulated without a gait aid (82.62±10.63) had significantly higher (P<.0) DEMMI scores than those who ambulated with an aid (64.1±12.40), providing evidence of known groups validity. No floor or ceiling effect was identified. The MCID was 7 points. The MDC₉₀ was 13 (95% CI, 8.76-17.05) points on the 100-point scale.
  
  
  CONCLUSIONS
  DEMMI scores in healthy, community-dwelling older adults are both valid and reliable.
authors.affiliation: Department of Physiotherapy, Monash University, Victoria, Australia. sarah.davenport@nh.org.au
authors.forename: Sarah J
authors.initials: SJ
authors.lastname: Davenport
authors.forename: Natalie A
authors.initials: NA
authors.lastname: de Morton
mesh_terms: D000203:Activities of Daily Living; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005260:Female; D016330:Frail Elderly / Q000523:psychology / Q000706:statistics & numerical data*; D005684:Gait; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D057187:Independent Living / Q000523:psychology / Q000706:statistics & numerical data*; D035002:Lower Extremity / Q000502:physiology; D008297:Male; D015588:Observer Variation; D009983:Orthopedic Equipment / Q000706:statistics & numerical data; D026741:Physical Therapy Modalities; D011788:Quality of Life; D015203:Reproducibility of Results; D012737:Sex Factors