Psychometric properties of the Activities-specific Balance Confidence Scale among individuals with a lower-limb amputation.
OBJECTIVE
To evaluate the internal consistency, test-retest reliability, and construct validity of the Activities-specific Balance Confidence (ABC) Scale among people who have a lower-limb amputation.


METHODS
Retest design.


METHODS
A university-affiliated outpatient amputee clinic in Ontario.


METHODS
Two samples of individuals who have unilateral transtibial and transfemoral amputation. Sample 1 (n=54) was a consecutive and sample 2 (n=329) a convenience sample of all members of the clinic population.


METHODS
Not applicable.


METHODS
Repeated application of the ABC Scale, a 16-item questionnaire that assesses confidence in performing various mobility-related tasks. Correlation to test hypothesized relationships between the ABC Scale and the 2-minute walk (2MWT) and the timed up-and-go (TUG) tests; and assessment of the ability of the ABC Scale to discriminate among groups based on amputation cause, amputation level, mobility device use, automatic stepping ability, wearing time, stair climbing ability, and walking distance.


RESULTS
Test-retest reliability (intraclass correlation coefficient) of the ABC Scale was .91 (95% confidence interval [CI], .84-.95) with individual item test-retest coefficients ranging from .53 to .87. Internal consistency, measured by Cronbach alpha, was .95. Hypothesized associations with the 2MWT and TUG test were observed with correlations of .72 (95% CI, .56-.84) and -.70 (95% CI, -.82 to -.53), respectively. The ABC Scale discriminated between all groups except those based on amputation level.


CONCLUSIONS
Balance confidence, as measured by the ABC Scale, is a construct that provides unique information potentially useful to clinicians who provide amputee rehabilitation. The ABC Scale is reliable, with strong support for validity. Study of the scale's responsiveness is recommended.
Miller
William C
WC
Faculty of Medicine, School of Rehabilitation Sciences, University of British Columbia, Vancouver Coastal Health Authority, Canada. bcmiller@telus.net
Deathe
A Barry
AB
Speechley
Mark
M
D000058:Accidental Falls; D000203:Activities of Daily Living; D000368:Aged; D000671:Amputation, Surgical / Q000009:adverse effects / Q000523:psychology* / Q000534:rehabilitation; D000674:Amputees / Q000523:psychology*; D000704:Analysis of Variance; D001294:Attitude to Health; D002183:Canes; D016002:Discriminant Analysis; D005239:Fear; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007866:Leg / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D004856:Postural Balance; D011594:Psychometrics; D020377:Self Efficacy; D012680:Sensitivity and Specificity; D018434:Sickness Impact Profile; D011795:Surveys and Questionnaires