Visual analogue scale foot and ankle: Validity and reliability of Thai version of the new outcome score in subjective form

Abstract

Background: Nowadays, measuring score in the form of subjective questionnaires is the important tool for clinical evaluation of the foot and ankle-related problems. Visual Analogue Scale-Foot and Ankle (VAS-FA) is the newly developed subjective questionnaire, which has sufficiency of validity and reliability from a previous study. Objective: Translate the original English version of VAS-FA into the Thai version and evaluate the validity and reliability of Thai VAS-FA in patients with foot and ankle-related problems. Material and Method: According to the forward-backward translation protocol, original VAS-FA was translated into the Thai version. Thai VAS-FA and validated Thai Short Form-36 (SF-36) questionnaires were distributed to 42 Thai patients to complete. For validation, Thai VAS-FA scores were correlated with SF-36 scores. For reliability, the test-retest reliability and internal consistency were analyzed. Results: Thai VAS-FA score demonstrated the sufficient correlations with physical functioning (PF), role physical (RP), bodily pain (BP) domains, and total score of SF-36 (statistically significant with p < 0.001 level and r > 0.5 values). The result of reliability revealed highly intra-class correlation coefficient as 0.995 from test-retest study. The internal consistency was excellent with Cronbach alpha: 0.995. Conclusion: The original VAS-FA score is a well-validated, subjective, visual-analogue-scale based outcome score. The Thai version of VAS-FA form maintained the validity and reliability of the original version. This newly translated-validated score can be distributed for the evaluation of the functions, symptoms, and limitation of activities in Thai patients with foot and ankle problems.