Development and validation of a video-animated tool for assessing mobility.
BACKGROUND
Existing self-report measures of mobility ignore important contextual features of movement and require respondents to make complex judgments about specific tasks. Thus, we describe the development and validation of a short form (sf) video-animated tool for assessing mobility, the Mobility Assessment Tool-MAT-sf.


METHODS
This study involves cross-sectional and longitudinal analyses examining the measurement properties of the MAT-sf. The MAT-sf consists of 10 animated video clips that assess respondents' level of proficiency in performing each task. The main outcome measures used for validation included the Pepper Assessment Tool for Disability (PAT-D), the Short Physical Performance Battery (SPPB), and 400-m walk test.


RESULTS
Participants (n = 234), 166 women and 68 men, had an average age of 81.9 years and a variety of comorbidities with 65.4% having high blood pressure. An average SPPB score of 8.6 (range 2-12) suggests that the study sample had evidence of compromised physical function but was quite heterogeneous. The MAT-sf had good content validity, excellent test-retest reliability (r = .93), and criterion-related validity with the PAT-D. Moreover, the MAT-sf added considerable variance to the prediction of both SPPB scores and 400-m gait speed over and above the PAT-D mobility subscale. The MAT-sf also discriminated between older adults who completed or failed the 400-m walk test.


CONCLUSIONS
The MAT-sf is an innovative psychometrically sound measure of mobility. It has utility in epidemiological studies, translational science, and clinical practice.
Rejeski
W Jack
WJ
Department of Health and Exercise Science, Wake Forest University, P.O. Box 7868, Winston-Salem, NC 27109, USA. rejeski@wfu.edu
Ip
Edward H
EH
Marsh
Anthony P
AP
Barnard
Ryan T
RT
D000368:Aged; D000369:Aged, 80 and over; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D051346:Mobility Limitation; D011237:Predictive Value of Tests; D011594:Psychometrics; D015203:Reproducibility of Results; D013647:Task Performance and Analysis; D014743:Videotape Recording
J Gerontol A Biol Sci Med Sci. 2001 Oct;56 Spec No 2:23-35
11730235
J Gerontol. 1994 Mar;49(2):M85-94
8126356
J Am Geriatr Soc. 2001 Nov;49(11):1539-43
11890596
JAMA. 2006 May 3;295(17):2018-26
16670410
J Gerontol A Biol Sci Med Sci. 2006 Nov;61(11):1157-65
17167156
JAMA. 1963 Sep 21;185:914-9
14044222
Am J Public Health. 1982 Dec;72(12):1373-9
6814269
Geriatr Gerontol Int. 2008 Mar;8(1):48-54
18713189
J Gerontol. 1966 Oct;21(4):556-9
5918309
JAMA. 1994 Oct 5;272(13):1036-42
8089886
J Am Geriatr Soc. 2000 May;48(5):493-8
10811541