Reliability and validity of Oswestry Disability Index among patients undergoing lumbar spinal surgery.

BACKGROUND: The objective of this study was to explore the internal consistency and factor structure of the Oswestry Disability Index among patients undergoing spinal surgery. The sample consisted of 1,515 patients who underwent lumbar spinal surgery at a university hospital between 2018 and 2021. METHODS: The patients responded to the Oswestry Disability Index within 2 months before surgery. Cronbach's alpha was used to assess the internal consistency. The factor structure was evaluated using exploratory and confirmatory factor analyses. RESULTS: The average age of 1,515 patients was 58.5 (SD 15.8) years and 53% were women. The mean ODI score was 43.4% (SD 17.4%). Of the patients, 68% underwent microsurgical excision of the lumbar intervertebral disc displacement or decompression of the lumbar nerve roots. The internal consistency of the Oswestry Disability Index was found to be good, with an alpha of 0.87 (95% CL 0.86 to 0.88). Exploratory factor analysis resulted in unidimensional structure. Item loadings on this retained factor were moderate to substantial for all 10 items. One-factor confirmatory factor analysis model demonstrated an acceptable fit. The correlations between the main factor "disability" and the individual items varied from moderate (0.44) to substantial (0.76). The highest correlations were observed for items "traveling", "personal care", and "social life". The lowest correlations were observed for the item "standing". CONCLUSIONS: The Oswestry Disability Index is a unidimensional and internally consistent scale that can be used to assess the severity of disability in patients undergoing lumbar spinal surgery. In the studied population, "traveling," "social life," "sex life" and "personal care" were the most important items to define the severity of disability, while "walking" and "standing" were the least important items. The generalizability of the results might be affected by the heterogeneity and modest size of the studied cohort. TRIAL REGISTRATION: Not applicable.

Back pain and radicular pain after lumbar microdiscectomy.

PURPOSE: It is generally expected that lumbar microdiscectomy affects radicular leg pain, but not so much local back pain. The primary objective was to evaluate if the trajectories of changes in pain severity follow similar patterns for back and radicular leg pain after lumbar microdiscectomy. The secondary objective was to investigate the associations between some preoperative parameters and the patterns of these trajectories. METHODS: Register-based retrospective study of 353 patients undergoing microdiscectomy in the lumbar spine. Linear mixed modelling was applied. RESULTS: The average age of the participants was 46 years and 44% were women. The developmental trajectories were similar for both back and leg pain. Pain level decrease during the first year after the surgery, slightly worsening later. No statistically significant interactions were detected of preoperative pain duration or severity, sex or age on the shapes of the trajectories. For every analyzed grouping factor, the 95% confidence intervals overlapped at every postoperative time point with one exception - worse preoperative back pain was statistically significantly associated with worse pain at three months and at the end of the two-year follow-up. CONCLUSION: After microsurgical discectomy, developmental curves for both back and radicular leg pain demonstrated similar patterns. Pain intensity decreased during the first year after the surgery. and slightly increased after that remaining, however, below the preoperative level. Age, sex, preoperative pain duration or preoperative intensity of leg pain were not associated with significant differences in the trajectories of pain severity after the surgery. In this study, severe preoperative back pain was the only factor, which was significantly associated with worse postoperative trajectory of pain intensity.