Cultural adaptation and psychometric validation of the exercise adherence Rating scale Mexican Spanish version (EARS-Mx)

Abstract

Objective

The aim has been to translate and cross-culturally adapt the Exercise Adherence Rating Scale (EARS) for Mexican Spanish speaking population with non-specific chronic low back pain and assess its psychometric properties.

Methods

The study had two phases: translation and cultural adaptation, followed by psychometric validation. Reliability was assessed with internal consistency (Cronbach's alpha) and test-retest reliability (intraclass correlation coefficient); validity with construct validity (Spearman's correlation) and factor analysis; sensitivity to change with effect size and standardized response mean difference; feasibility by completion time in seconds; and ceiling/floor effects were calculated.

Results

A total of 161 subjects were included. Cronbach's alpha (0.93; 95% CI 0.92–0.95) indicated good internal consistency, and intraclass correlation (0.95; 95% CI: 0.89–0.97) showed excellent test-retest reliability. Weak correlations between the EARS vs. the Visual Analogue Pain Rating Scale and the Roland Morris Disability Questionnaire were found (r = −0.29 and r = 0.00 respectively). All effect size values indicated that the scale presented a significant sensitivity to change. The average time to complete the EARS-Mx was 219 s. No ceiling or floor effect was detected.

Conclusion

The EARS-Mx showed semantic, conceptual, idiomatic, content and operational equivalence with respect to the original scale, and appropriate metric properties of reliability, validity, sensitivity to change and feasibility.