Validity, reliability and responsiveness of the Hungarian version of the spine oncology study group outcomes questionnaire.

Background Context: The incidence of bone metastases is increasing due to advancements in cancer treatment, making it essential to monitor patients' health-related quality of life (HRQOL). Patients diagnosed with spinal metastases often experience persistent pain and functional decline. The use of specific patient-reported outcome measures in spinal tumors can help assess quality of life and treatment outcome.

Purpose: This study aims to cross-culturally adapt and validate the Spine Oncology Study Group Outcomes Questionnaire (SOSGOQ) into Hungarian to accurately assess the HRQOL of patients diagnosed with spinal metastases.

Study Design/setting: A prospective study was conducted at a tertiary referral hospital among patients treated for spinal metastases.

Patient Sample: 50 patients with spinal metastases were included into the study. The median age of the study population was 52 years, ranging from 30 to 82 years. The gender distribution was 27 men and 33 women. The most common primary tumor was breast cancer, followed by lung cancer and prostate cancer.

Outcome Measures: SOSGOQ, EuroQol-5D index and EuroQol-VAS.

Methods: After translation and cross-cultural adaptation of SOSGOQ, the validity of the SOSGOQ was assessed by correlating it with the EQ-5D index and VAS using Spearman's rank correlation. Reliability was evaluated with the calculation of intraclass correlation coefficient (ICC) and standard error of measurement (SEM), from which the minimal detectable change (MDC95%) was calculated (2.77*SEM). Responsiveness was expressed by the change in group mean scores from pre-surgery to three months post-surgery and the effect size (Cohen's d). Receiver operating characteristic (ROC) analysis was also performed considering different dimensions of clinical outcome.

Results: No significant floor or ceiling effect was observed for the total SOSGOQ score. The Spearman rank correlation between the SOSGOQ and the EQ-5D index showed a strong association (rho = 0.887, p < 0.001), as did the correlation between the SOSGOQ and the EQ-VAS (rho = 0.653, p < 0.001). Hungarian SOSGOQ proved to be a highly reliable PROM characterized by ICC = 0.95 SEM = 3.9 points, and MDC95 = 11 points. The responsiveness analysis indicates that the SOSGOQ can detect clinical changes in patients with spinal tumors performing better in this context than EQ-5D.

Conclusions: The Hungarian SOSGOQ is a reliable and valid tool for assessing the quality of life in patients diagnosed with spinal metastases. The outstanding responsiveness of this condition-specific PROM was also demonstrated in our study.