Defining Normative Quality Metrics in Complex High-Risk Deformity Cases: Results from the Scoli-Risk 1 Study

Abstract

IntroductionQuality metrics are a component of the value calculation, and reflect the risk of care. There is significant variability in complication rates, and quality metric standards in spinal surgery. Case complexity or surgical invasiveness is an important predictor of perioperative complications, and normative standards for quality metrics should be stratified by case complexity. The purpose of this study is to define normative quality metrics for complex, high-risk spinal deformity cases, and to provide a standard and baseline data that may guide quality improvement in comparative research. Material and MethodsSecondary analysis of a prospective, international multicenter observational study (Scoli-Risk1) The study cohort included adults with spinal deformity in the cervicothoracic or thoracolumbar regions. Quality metrics include cumulative readmission and reoperation rates (30, 90, 180 days), wound infection, and DVT rates. Chi Square analysis is used to measure the relationship between osteotomy type and readmission and reoperation. Linear regression is used to determine the association of age and procedure with readmission and reoperation. Results273 patients from the Scoli-Risk 1 study were included in the analysis. Cumulative readmission rates were 7.7 (4.8;11.5), 13.2 (9.4;17.8), 16.5 (12.3;21.4) percent at 30, 90 and 180 days after index surgery. Reoperation rates were 14.7 (10.7;19.4), 17.6 (13.3;22.6), 20.1 (15.6;25.4) percent at 30, 90 and 180 days after index surgery. Age was a significant predictor of readmission during the first 180 days after surgery (OR1.388 (1.068;1.803)), but not a significant predictor of the need for reoperation (OR=1.109 (0.903;1.361)). Osteotomy type (PSO/VCR vs SPO) was not a significant predictor of the need for readmission (p = 0.986) or reoperation (p = 0.753). The overall infection rate was 7.0%, including 3.3% deep infections. The rate of DVT was 3.7%. ConclusionNormative quality metrics are not established for complex deformity surgery in adult patients. This paper demonstrates that readmissions and reoperations in complex spinal reconstruction in adults occur at a higher rate than expected rates in less complex spine procedures. Age is an important independent predictor of readmission, but not the need for reoperation. For each decade older, patients are 1.4 times more likely to be readmitted within 6 months of surgery. This data may be useful to provide normative data for comparative studies of surgical outcomes with similar magnitude of deformity treated with operations of comparable invasiveness.