Measuring clinically relevant improvement after lumbar spine surgery: is it time for something new?

Minimum clinically important difference (MCID) for patient-reported outcome measures is commonly used to assess clinical improvement. However, recent literature suggests that an absolute point-change may not be an effective or reliable marker of response to treatment for patients with low or high baseline patient-reported outcome scores. The multitude of established MCIDs also makes it difficult to compare outcomes across studies and different spine surgery procedures. To determine whether a 30% reduction from baseline in disability and pain is a valid method for determining clinical improvement after lumbar spine surgery. Retrospective analysis of prospective data from a national spine registry, the Quality Outcomes Database. There were 23,280 participants undergoing elective lumbar spine surgery for degenerative disease who completed a baseline and follow-up assessment at 12 months. Patient-reported disability (Oswestry Disability Index [ODI]), back and leg pain (11-point Numeric Rating Scale [NRS]), and satisfaction (NASS scale). Patients completed baseline and a 12-month postoperative assessment to evaluate the outcomes of disability, pain, and satisfaction. The change in ODI and NRS pain scores was categorized as met (≥30%) or not met (