An Independent Interobserver Reliability and Intraobserver Reproducibility Evaluation of Spinal Instability Neoplastic Score and Kostuik Classification Systems for Spinal Tumor

Abstract

Most patients with spinal tumors suffer no symptoms or have mild symptoms, but about 14% of patients have refractory pain caused by mechanical instability, or symptoms of spinal cord damage caused by epidural spinal cord compression. The Spinal Instability Neoplastic Score (SINS) and Kostuik classification are commonly used to evaluate spinal stability, and help to make a more detailed operation plan. The objectives of this study are to evaluate the reliability and reproducibility of the SINS and Kostuik classification, and to explore their clinical application value. All 80 patients with spinal tumors were enrolled. Six spine surgeons who have certain clinical experience were selected. Patients were scored according to the SINS scoring system and classification was determined according to the Kostuik system. We used Fleiss and Cohen κ values to check the coefficient consistency for multifactors. We used Cohen κ value to check the interobserver reliability and intraobserver reproducibility. After 12 weeks, we repeated the analysis. The interobserver reliability and intraobserver reproducibility of the SINS scoring system were near perfect with values of 0.831 and 0.874, respectively. The interobserver reliability and intraobserver reproducibility of the Kostuik classification system were moderate with values of 0.505 and 0.595, respectively. Compared with the Kostuik classification system, the SINS scoring system has better interobserver reliability and intraobserver reproducibility, which can be widely used in clinical practice and has great significance in the decision-making of spinal tumor treatment. Although the Kostuik classification system is often used in clinical practice, it shows inferior reliability and reproducibility in our study.