Objective: To develop and test the validity and reliability of the Thai version of the Toronto Extremity Salvage Score [TESS] questionnaire for patients with bone and soft-tissue Sarcoma.

Materials and Methods: The Thai version of the TESS was developed by translation, back translation, and review for consensus. Then the questionnaire’s validity and reliability was tested in 140 patients (70 upper extremities and 70 lower extremities). The validity was tested in two aspects, by content validity and criterion validity. The content validity was done through a physician-rated scoring for content validity index [CVI]. The criterion validity was measured by comparing with the clinical-rated Musculoskeletal Tumor Society Score [MSTS] by Pearson’s correlation coefficient (r). The reliability was tested in two aspects namely internal consistency by Cronbach’s alpha coefficient and external consistency by intraclass coefficient [ICC].

Results: TESS was translated into a Thai version and tested in Thai patients. For upper extremity TESS, the mean score was 82.15±21.9. The validity was acceptable (CVI = 0.90, r = 0.612). The reliability was high (Cronbach’s alpha = 0.975, ICC = 0.910). Regarding lower extremity TESS, the mean score was 87.99±14.39. The validity was acceptable (CVI = 0.95, r = 0.636). The reliability was high (Cronbach’s alpha = 0.981, ICC = 0.810).

Conclusion: The Thai version of TESS was valid and reliable to evaluate functional outcome in Thai bone and soft tissue sarcoma patients.

Keyword: Toronto extremity salvage score [TESS], Functional outcome, Thai version, Sarcoma, Validity, Reliability