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 and 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 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 kappa=0.81 (with 95% CI, range 0.04). Less agreement was observed in the interobserver evaluation test with the mean kappa=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.