Cross cultural adaptation of the TENDINopathy severity assessment - Achilles (TENDINS-A) for Spanish speaking...

The TENDINopathy Severity assessment - Achilles (TENDINS-A) was developed as a patient-reported outcome measure of Achilles tendinopathy related disability but is limited to the English language. The objective of this study was to cross-culturally adapt the TENDINS-A to be used in Spanish speaking populations and assess its measurement properties.

The TENDINS-A was cross-culturally adapted using a multistep process then administered online to individuals with Achilles tendinopathy, non-Achilles tendinopathy foot pain, and pain-free controls. Test-retest reliability of the TENDINS-A Spanish was determined using inter-class coefficients (ICC). Internal consistency and structural validity were assessed using Rasch analysis. Discriminate validity was measured comparing the TENDINS-A Spanish scores between the three groups. Convergent validity was assessed using correlations between the TENDINS-A, heel raise pain, and Victorian Institute of Sport Assessment-Achilles (VISA-A).

The TENDINS-A Spanish Total score demonstrated excellent test re-test reliability (ICC(95%CI): 0.932(0.897 to 0.955) and excellent internal consistency (person reliability = 0.89). There was evidence of structural validity of the TENDINS-A Spanish for a 3-factor structure (First contrast from PCA of residuals has Eigenvalue <2). TENDINS-A Spanish Total scores were higher in individuals with Achilles tendinopathy compared to those with non-Achilles tendinopathy foot pain (Mean Dif (95%CI): 19.8%(6.5% to 33.0%) and pain-free controls (46.7%(32.8% to 60.6%). The TENDINS-A Spanish showed convergent validity (r (95%CI)) with moderate to strong correlations with heel raise pain (0.86(0.79 to 0.91), and VISA-A Spanish (-0.64(-0.49 to -0.74) CONCLUSIONS: The TENDINS-A Spanish is a reliable and valid measure for Achilles tendinopathy related disability in Spanish speaking populations.