Psychometric properties of the Spanish version of the Cumberland Ankle Instability Tool

Purpose: To estimate the psychometric properties of the Spanish version of the Cumberland Ankle Instability Tool (CAIT-Sv). Method: One hundred and seventy-one subjects participated. The psychometric properties tested for CAIT-Sv were internal consistency with Cronbach's alpha (n = 171) in the first measurement; test-retest reliability using the intraclass correlation coefficient (ICC2,(1)) (n = 171) in two measurements separated by one week; criterion validity by ICC2,1 between the original CAIT and CAIT-Sv in two measurements separated by two weeks for a subgroup of 54 bilingual subjects; ceiling and floor effects (n = 78 subjects with a history of at least one ankle sprain), and responsiveness using Cohen's d in a subgroup of 25 subjects with a history of at least one ankle sprain and a score <= 24 points on the CAIT-Sv and treated with a rehabilitation program during four weeks. Results: Internal consistency was excellent (Cronbach's alpha : 0.8-0.84). Test-retest reliability was high (ICC2,1: 0.95). Criterion validity was high (ICC2,1: 0.91; 95% CI: 0.84-0.94; p<0.001 for dominant ankle). There were no ceiling (9%) and floor (0%) effects. Responsiveness was moderate (Cohen's d: 0.6995; CI: 0.11-1.27). Conclusions: CAIT-Sv is a reliable instrument with high criterion validity to measure the presence and severity of chronic ankle instability (CAI) in the Spanish population.