Minimum clinically important difference, substantial clinical benefit, and patient acceptable symptomatic state for patients with spinal metastasis who underwent surgical treatment: a multicenter prospective clinical study.

Objective: There is increasing emphasis on patient-reported outcomes (PROs) in assessing surgical efficacy, especially in patients with spinal metastasis (SM). The updated version of the Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ 2.0) is a disease-specific tool, while the EQ-5D-5L is a general quality-of-life instrument. The aim of this study was to establish the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) thresholds for these tools in patients undergoing surgery for SM.

Methods: A multicenter prospective observational study of patients with SM who underwent surgical treatment from January 2020 to December 2022 across 4 institutions was performed, and patients were followed for 6 months. Patients completed the SOSGOQ 2.0 and EQ-5D-5L at baseline and 1-, 3-, and 6-month follow-up assessments. Anchor- and distribution-based methods were used to calculate the MCID, SCB, and PASS. Clinical performance was compared between the two tools.

Results: A total of 260 patients (138 males, mean age 62.4 years) who underwent surgery for SM were included. Surgery resulted in significant improvements in both PRO measures. The MCID was 19.4 for the SOSGOQ 2.0 total score and 19.6 for the visual analog scale of the EQ-5D-5L. A higher percentage of patients achieved clinically meaningful outcomes per the SOSGOQ 2.0, indicating superior sensitivity and clinical utility over the EQ-5D-5L.

Conclusions: Compared with the EQ-5D-5L, the SOSGOQ 2.0 demonstrated higher sensitivity in assessing functional improvements in patients with SM, making it the preferred tool in clinical settings. Further research is recommended for long-term validation.