Volume 87, Issue 9 , Pages 1235-1241, September 2006
The Cumberland Ankle Instability Tool: A Report of Validity and Reliability Testing
Abstract
Hiller CE, Refshauge KM, Bundy AC, Herbert RD, Kilbreath SL. The Cumberland Ankle Instability Tool: a report of validity and reliability testing.
Objective
To test the Cumberland Ankle Instability Tool (CAIT), a 9-item 30-point scale, for measuring severity of functional ankle instability.
Design
Cross-sectional study.
Setting
General community.
Participants
Volunteer sample of 236 subjects.
Interventions
Not applicable.
Main Outcome Measures
Concurrent validity by comparison with the Lower Extremity Functional Scale (LEFS) and a visual analog scale (VAS) of global perception of ankle instability by using the Spearman ρ. Construct validity and internal reliability with Rasch analysis using goodness-of-fit statistics for items and subjects, separation of subjects, correlation of items to the total scale, and a Cronbach α equivalent. Discrimination score for functional ankle instability by maximizing the Youden index and tested for sensitivity and specificity. Test-retest reliability by intraclass correlation coefficient, model 2,1 (ICC2,1).
Results
There were significant correlations between the CAIT and LEFS (ρ=.50, P<.01) and VAS (ρ=.76, P<.01). Construct validity and internal reliability were acceptable (α=.83; point measure correlation for all items, >0.5; item reliability index, .99). The threshold CAIT score was 27.5 (Youden index, 68.1); sensitivity was 82.9% and specificity was 74.7%. Test-retest reliability was excellent (ICC2,1=.96).
Conclusions
CAIT is a simple, valid, and reliable tool to measure severity of functional ankle instability.
Key Words: Ankle , Joint instability , Questionnaires , Rehabilitation , Sprains and strains
Supported by the National Health and Medical Research Council of Australia.No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the author(s) or upon any organization with which the author(s) is/are associated.
PII: S0003-9993(06)00519-3
doi:10.1016/j.apmr.2006.05.022
© 2006 American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.
Volume 87, Issue 9 , Pages 1235-1241, September 2006
