Defining Clinically Meaningful Values in Health-Related Quality of Life (EQ-5D) Following Lumbar Endoscopic Spine Surgery

Introduction: Full Endoscopic Spine Surgery (FESS) has emerged as an effective alternative to Minimally Invasive Spine Surgery, showing fast recoveries in several clinical trials and significant reduction of perioperative morbidity. Patient-reported outcome measures (PROMs) are essential to assess treatment efficacy. Currently, no clinical benchmarks exist for meaningful change in health-related quality of life measure EQ-5D for lumbar FESS patients. This study aims to define the minimal clinically important difference (MCID) and substantial clinical benefit (SCB) for EQ-5D and identify factors associated with clinical benefit achievement.

Methods: This multicentric prospective study included adults who underwent FESS for lumbar degenerative spine disease. Patients were monitored postoperatively via a smartphone application, PROMs including EQ-5D and Oswestry Disability Index (ODI), were collected preoperatively and one-year post-surgery. MCID and SCB thresholds of absolute and percentage changes were established using anchor- and distribution-based methods. ODI was used as an anchor and ROC analysis determined optimal cutoffs. Then, Multivariable logistic regression identified predictors of achieving MCID and SCB.

Results: A total of 812 patients were analyzed, with 129 included for anchor-based analysis. Significant improvements were observed in ODI and EQ-5D scores at 12 months postoperatively. The MCID for EQ-5D, based on an 11-point ODI improvement, was defined as a 0.28 net improvement or 51% of maximum possible improvement, (AUCs 0.87-0.89). The SCB, based on a 19-point ODI improvement, was a net improvement of 0.41 or 71% of maximum possible improvement, (AUCs 0.86-0.9). Distribution-based methods defined MCID and SCB as 0.16 and 0.64, respectively. Age, BMI, and baseline disease severity were the most influential factors in achieving clinical benefit.

Conclusion : This study defines clinically meaningful thresholds for EQ-5D improvement following lumbar FESS, providing benchmarks for outcomes evaluation. Age, BMI, and baseline disease severity were found to influence the likelihood of achieving clinical benefit, offering insights for patient selection.