title: The MAT-sf: clinical relevance and validity.
abstract: BACKGROUND
  The measurement of mobility is essential to both aging research and clinical practice. A newly developed self-report measure of mobility, the mobility assessment tool-short form (MAT-sf), uses video animations to improve measurement accuracy/precision. Using a large baseline data set, we recalibrated the items, evaluated the extent to which older patients' self-efficacy (i.e., confidence) for walking was related to MAT-sf scores beyond their actual 400-m walk time, and assessed the relationship of the MAT-sf with body mass index and other clinical variables.
  
  
  METHODS
  The analyses employed baseline data from the Lifestyle Interventions and Independence for Elders Study.
  
  
  RESULTS
  Item recalibration demonstrated that the MAT-sf scoring algorithm was robust. In an analysis with 400-m walk time and self-efficacy regressed on the MAT-sf, both variables shared unique variance with the MAT-sf (p < .001). The MAT-sf was inversely related to several comorbidities, most notably hypertension and arthritis (p < .001), and scores were lowest when body mass index ≥ 35 kg/m(2). Finally, MAT-sf scores were directly related to Short Physical Performance Battery scores, inversely related to difficulty with activities of daily living (p < .001) and higher for men than for women (p < .001).
  
  
  CONCLUSIONS
  The findings extend the validity and clinical utility of this innovative tool for assessing self-reported mobility in older adults. Longitudinal data on the MAT-sf from the Lifestyle Interventions and Independence for Elders Study will enable us to evaluate the relative contributions of self-report and performance-based measures of mobility on important health outcomes.
authors.affiliation: Wake Forest University, Box 7868, Department of Health and Exercise Science, Winston-Salem, NC 27109. rejeski@wfu.edu.
authors.forename: W Jack
authors.initials: WJ
authors.lastname: Rejeski
authors.forename: Anthony P
authors.initials: AP
authors.lastname: Marsh
authors.forename: Stephen
authors.initials: S
authors.lastname: Anton
authors.forename: Shyh-Huei
authors.initials: SH
authors.lastname: Chen
authors.forename: Tim
authors.initials: T
authors.lastname: Church
authors.forename: Thomas M
authors.initials: TM
authors.lastname: Gill
authors.forename: Jack M
authors.initials: JM
authors.lastname: Guralnik
authors.forename: Nancy W
authors.initials: NW
authors.lastname: Glynn
authors.forename: Abby C
authors.initials: AC
authors.lastname: King
authors.forename: Julia
authors.initials: J
authors.lastname: Rushing
authors.forename: Edward H
authors.initials: EH
authors.lastname: Ip
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001168:Arthritis / Q000150:complications; D061827:Dimensional Measurement Accuracy; D005260:Female; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D006973:Hypertension / Q000150:complications; D008297:Male; D051346:Mobility Limitation; D011930:Reaction Time; D015203:Reproducibility of Results; D012307:Risk Factors; D020377:Self Efficacy; D012737:Sex Factors; D014741:Video Recording / Q000379:methods; D016138:Walking / Q000502:physiology / Q000523:psychology
keywords: Geriatric assessment; MAT-sf; Mobility; Physical function