Independent inter and intra-observer agreement of the Schizas’s classification of degenerative lumbar stenosis. Comparison among three levels of surgical training

INTRODUCTION AND OBJECTIVES:Lumbar spinal stenosis is a common age-related condition that affects the quality of life. Multiple classifications have been developed to quantify the severity of stenosis affecting comparison between studies and homogenous communication among surgeons and researchers. Even though this classification has not shown a direct clinical correlation, Schizas's classification appears to be a simple method to assess stenosis. Our objective was to evaluate the inter and intraobserver independent agreement of the Schizas's classification to assess stenosis severity. Additionally, we aimed to compare agreement among three levels of training in spine surgery. MATERIALS AND METHODS:An independent inter and intra observer agreement was conducted among junior, senior orthopedic residents and attending spine surgeons. Ninety lumbar levels from 30 patients were evaluated by 16 observers. Weighted kappa agreement was used. RESULTS:Overall interobserver and intraobserver agreement was of 0.57 (95% CI=0.52-0.63) and 0.69 (0.55-0.79), respectively. Interobserver agreement according to level of training yielded values of 0.53 (0.46-0.60) for junior residents, 0.61 (0.54-0.67) for senior residents and 0.67 (0.59-0.74) for attendings. Intraobserver agreement was of 0.54 (0.48-0.60) for junior, 0.60 (0.55-0.66) for senior and 0.66 (0.60-0.72) for attendings. CONCLUSION:The Schizas's classification showed moderate interobserver and substantial intraobserver agreement. Among attending surgeons, substantial inter and intraobserver agreement was observed. The classification allowed acceptable communication among trained spine surgeons.