The Locomotor Capabilities Index; validity and reliability of the Swedish version in adults with lower limb amputation

BACKGROUND The Locomotor Capabilities Index (LCI) is a validated measure of lower-limb amputees' ability to perform activities with prosthesis. We have developed the LCI Swedish version and evaluated its validity and reliability. METHODS Cross-cultural adaptation to Swedish included forward/backward translations and field testing. The Swedish LCI was then administered to 144 amputees (55 women), mean age 74 (40-93) years, attending post-rehabilitation prosthetic training. Construct validity was assessed by examining the relationship between the LCI and Timed "Up-and-Go" (TUG) test and between the LCI and EQ-5D health utility index in 2 subgroups of 40 and 20 amputees, respectively. Discriminative validity was assessed by comparing scores in different age groups and in unilateral and bilateral amputees. Test-retest reliability (1-2 weeks) was evaluated in 20 amputees (14 unilateral). RESULTS The Swedish LCI showed good construct convergent validity, with high correlation with the TUG (r = -0.75) and the EQ-5D (r = 0.84), and discriminative validity, with significantly worse mean scores for older than younger and for bilateral than unilateral amputees (p < 0.01), and high internal consistency (Cronbach alpha 0.95). In test-retest reliability the intraclass correlation coefficient was 0.91 (95% CI 0.79-0.96) but for the unilateral amputees was 0.83 (95% CI 0.56-0.94). Ceiling effect occurred in 23%. CONCLUSION The Swedish version of the LCI demonstrated good validity and internal consistency in adult amputees. Test-retest reliability in a small subsample appears to be acceptable. The high ceiling effect of the LCI may imply that it would be most useful in assessing amputees with low to moderate functional abilities.