Spanish Translation, Cross-Cultural Adaptation and Validation of the Spine Oncology Study Group Outcomes...

Spinal metastases significantly impair health-related quality of life (HRQoL), particularly neurological function, pain, and physical independence. The Spinal Oncology Study Group Outcome Questionnaire (SOSGOQ 2.0) is a disease-specific PROM, but no validated Spanish version exists. This study aimed to translate, culturally adapt, and validate the SOSGOQ 2.0 for Spanish-speaking patients with spinal metastases.

Following Beaton et al.'s cross-cultural adaptation guidelines, the SOSGOQ 2.0 was forward- and back-translated, reviewed by experts, and pretested with 10 patients. Psychometric validation was performed prospectively in 81 patients. Internal consistency was assessed using Cronbach's α, test-retest reliability using intraclass correlation coefficients (ICC, n = 21), and construct validity through correlations with SF-36 and EQ-5D domains. Known-groups validity was analyzed according to neurological status (ASIA scale) and pain severity (VAS).

The Spanish SOSGOQ 2.0 showed excellent internal consistency (overall α = 0.89; domain range 0.70-0.93) and high test-retest reliability (ICC = 0.88; 95% CI, 0.81-0.93). Convergent validity was supported by moderate-to-strong correlations with SF-36 domains (r = 0.67-0.71). Known-groups analysis demonstrated expected differences between ambulatory (ASIA D-E) and non-ambulatory (ASIA A-C) patients, and between low (VAS ≤4) and high pain (VAS ≥5) groups. Neurological improvement post-treatment was observed in 32% of the patients. The questionnaire was well understood and culturally appropriate.

The Spanish SOSGOQ 2.0 is a reliable and valid tool for assessing HRQoL in Spanish-speaking patients with spinal metastases, enabling standardized, disease-specific outcome measurement and supporting patient-centered care and international research collaboration.