SRS-22R Minimum Clinically Important Difference and Substantial Clinical Benefit After Adult Lumbar Scoliosis Surgery.

Abstract

STUDY DESIGN:Longitudinal cohort. OBJECTIVES:To determine if the minimum clinically important difference (MCID) and substantial clinical benefit (SCB) thresholds for the Scoliosis Research Society-22R (SRS22R) domains in patients with degenerative lumbar scoliosis are similar to those in patients with adult spinal deformity (ASD) with fusions extending into the thoracic spine. SUMMARY OF BACKGROUND DATA:The MCID and SCB thresholds for the SRS22R domains in patients with ASD and adolescent idiopathic scoliosis have been reported. METHODS:Patients enrolled in the NIH-sponsored Adult Symptomatic Lumbar Scoliosis (ASLS) trial who underwent surgery and completed the SRS22R preoperative and the SRS30 one-year postoperative were identified. One-year postoperative answers to the last eight questions of the SRS30 were used as anchors to determine the MCID and SCB for the Pain, Appearance, and Activity domains, and the Subscore and Total score using receiver operating characteristic (ROC) curve analysis. RESULTS:The sample population consisted of 147 patients. A total of 132 (89%) were females with a mean age of 59.4 years. There was a statistically significant improvement in all SRS22R scores from preoperative to one-year postoperative. There was also a statistically significant difference in domain scores among the different responses to the anchors. According to the ROC analysis, MCID was 1.17 for Appearance, 0.40 for Activity, 0.60 for Pain, 0.53 for Subscore, and 0.77 for Total; and SCB was 1.67 for Appearance, 0.60 for Activity, 0.62 for Subscore, and 1.11 for Total score. These are similar to previous reports of MCID and SCB thresholds for ASD patients who underwent fusion to the thoracic spine. CONCLUSION:The MCID and SCB thresholds for the SRS22R domains in patients with adult symptomatic lumbar scoliosis are very similar to the threshold values previously reported for adult deformity patients. LEVEL OF EVIDENCE:Level II.