Surgical Resection of Intradural Extramedullary Spinal Tumors: Patient Reported Outcomes and Minimum Clinically Important Difference

Study design Analysis of prospectively collected longitudinal web-based registry data. Objective To determine relative validity, responsiveness, and minimum clinically important difference (MCID) thresholds in patients undergoing surgery for intradural extramedullary (IDEM) spinal tumors. Summary of background data Patient-reported outcomes (PROs) are vital in establishing the value of care in spinal pathology. There is limited availability of prospective, quality studies reporting PROs for IDEM spine tumors. Methods . A total of 40 patients were analyzed. Baseline, postoperative 3-month, and 12-month PROs were recorded: Oswestry Disability Index or Neck disability Index (ODI/NDI), Quality of life EuroQol-5D (EQ-5D), Short Form-12 (SF-12), Numeric Rating Scale (NRS)-pain scores. Responders were defined as those who achieved a level of improvement one or two, after surgery, on health transition index (HTI) of SF-36. Receiver-operating characteristic curves were generated to assess the validity of PROs, and the difference between standardized response means (SRMs) in responders versus nonresponders was utilized to determine the relative responsiveness of each PRO measure. MCID thresholds were derived using previously reported minimal detectable change approach. Results A significant improvement across all PROs at 3-months and 12-months follow up was noted. The derived MCID thresholds were 13.9 points: ODI/NDI, 0.14 quality adjusted life years: EQ-5D, 2.8 points: SF-12PCS and 10.7 points: SF-12MCS, 1.9 points: NRS-back/neck pain, and 1.8 points: NRS-leg/arm pain. SF-12PCS was most accurate discriminator of meaningful improvement (area under the curve, AUC-0.83) and most responsive (SRM-1.36) to postoperative improvement. EQ-5D, ODI/NDI, NRS-pain scores were all accurate discriminator (AUC-0.7-0.8) and responsive measures (0.97-0.67) of meaningful postoperative improvement. SF-12MCS was neither a valid discriminator (AUC-0.48) nor a responsive measure (SRM: -1.5) of outcome. Conclusion Surgical resection of IDEM spinal tumors provides significant and sustained improvement in quality of life, general health, disability, and pain at 12-month after surgery. The surgically resected IDEM-specific clinically meaningful thresholds are reported. All the PROs reported in this study can accurately discriminate responders and nonresponder based on SF-36 HTI index except for SF-12 MCS. Level of evidence 3.