Validity and reliability of the Thai version of the Spine Oncology Study Group Outcomes Questionnaire version 2.0 to assess Quality of Life in Patients with Spinal Metastasis

Abstract

Background ContextThe Spine Oncology Study Group Outcomes Questionnaire version 2.0 (SOSGOQ2.0) is a spinal metastasis (SM)-specific quality of life (QoL) questionnaire that was previously reported to have good reliability and validity. There is currently no Thai version of the SOSGOQ 2.0. (TH-SOSGOQ2.0). PurposeTo assess the psychometric properties of the TH-SOSGOQ 2.0. Study Design/SettingCross-sectional study. Faculty of Medicine Siriraj Hospital, Mahidol University. Patient SamplePatients who were confirmed diagnosis of metastatic spinal disease, age 18 to 75 years, and having already undergone surgery and/or radiotherapy for the treatment of spinal metastasis. Outcome MeasuresValidity and reliability of the TH-SOSGOQ 2.0 to assess QoL in Patients with SM. MethodsUsing the forward-backward translation technique, the SOSGOQ2.0 was translated into Thai language to create the TH-SOSGOQ2.0. SM patients were prospectively enrolled and evaluated for patient QoL using both the TH-SOSGOQ2.0 and the EQ-5D-5L (Thai version) at baseline and 3 months after treatment. Construct validity was assessed using multi-trait scaling analysis, confirmatory factor analysis, and correlation with EQ-5D-5L. Test-retest reliability was assessed in a subgroup of patients who took the TH-SOSGOQ2.0 two times one week apart. ResultsSixty-eight patients (mean age: 57 years; 30 males, 38 females) were included. The Cronbach's alpha values for the total score, physical function, neurological function, pain, mental health, social function, and post-therapy domains were 0.87, 0.89, 0.91, 0.84, 0.82, 0.75, and 0.85, respectively. Good reliability was demonstrated (interclass correlation coefficient range: 0.70-0.84), except for the social function domain (0.60). Regarding concurrent validity, the TH-SOSGOQ2.0 domains demonstrated moderate to good correlation with the corresponding EQ-5D-5L 9 (Thai version) domains (range: -0.32 to -0.78). Physical function was the most well-correlated domain with the EQ-5D-5L (Thai version) (-0.77). ConclusionsTH-SOSGOQ2.0 demonstrated good reliability and validity for assessing QoL in Thai SM patients.