Rates, Causes, and Predictive Factors of Hospital Readmissions After Spine Surgery for Lumbar Spinal Stenosis: A Nationwide Retrospective Cohort Study.

Abstract

Objective: This study aimed to determine the rates, causes, and predictive factors of readmissions at different periods following spine surgery, up to 180 days.

Methods: This study utilized data from the 2018 to 2019 Nationwide Readmissions Database and included four postoperative periods: 0 to 7 days, 8 to 30 days, 31 to 90 days, and 91 to 180 days. The causes of readmissions and potential predictive factors were systematically identified. All analyses were performed for each period.

Results: For the 180,281 patients (mean age, 65.4 years) included, 2.4% were readmitted between 0 and 7 days, 3.5% between 8 and 30 days, 3.7% between 31 and 90 days, and 4.3% between 91 and 180 days (cumulative rates: 2.4%, 5.9%, 9.3%, and 12.1%, respectively). The causes of readmissions varied across different periods: surgical site-related causes predominated within the first 30 days, whereas nonsurgical site-related causes were more prevalent from 31 to 180 days; other surgical care complication (e.g., infection) was the most prevalent cause between 0 and 7 days (10.7%) and between 8 and 30 days (29.2%), while spondylopathies/spondyloarthropathy (e.g., spinal stenosis) were the leading causes between 31 and 90 days (12.6%) and between 91 and 180 days (17.5%). The predictive factors associated with readmissions also varied across different periods. For example, patients who underwent fusion was associated with a decreased risk of readmissions between 31 and 180 days (e.g., between 91 and 180 days: odds ratio [OR], 0.79; 95% confidence interval [CI], 0.72-0.86; p<0.001), rather than between 0 and 30 days (e.g., between 0 and 7 days: OR, 0.99; 95% CI, 0.90-1.08; p=0.81).

Conclusion: About 6% of patients with lumbar spinal stenosis who underwent spine surgery were readmitted within 30 days and 12% by 180 days. The causes of readmissions and predictive factors varied by period, providing valuable insights for quality improvement efforts and the burden of readmission reductions.