Intraobserver and interobserver reproducibility of the novel transcription method for selection of potential nerve root compression in MRI study in degenerative disease of the lumbar spine

BACKGROUND: Degenerative disease of the lumbar spine is characterized by symptoms related to the affected nerve root. A recently described method allows the classification of the roots in relation to the occurrence of compression on its course. This method can serve as a clinical selection tool and decision support for semi-invasive pain therapy in back pain patients. MATERIAL/METHODS: We examined 40 lumbar spine MRIs in 3 sessions of transcription each, according to the method being evaluated. Every MRI evaluation was performed by each of 3 different observers. Intra- and interobserver reproducibility was calculated using chance-corrected agreement using a weighted kappa (κ) value with quadratic weights to assess reliability for each nerve root separately. RESULTS: We found high intraobserver agreement in indication of the root with most pronounced interference due to potential compression by degenerative changes, at the level mean κ=0.81 (with 95% CI, range 0.04). Less agreement was observed in the interobserver evaluation test with the mean κ=0.75 (95% CI within the range not exceeding 0.03), although it still reached the substantial agreement. CONCLUSIONS: This zstudy provides evidence for substantial inter- and intraobserver agreement for the decision support method allowing selection of the most serious nerve structure compression in degenerative disease of the lumbar spine based on of the MRI description.