What are the predictors of prolonged length of stay following single-stage lumbar fusion for grade 2 spondylolisthesis? A Spine CORe™ analysis of QOD data

OBJECTIVE: Prolonged hospital length of stay (LOS) is an increasingly important quality metric among regulators and payers that has been associated with worse patient outcomes and decreased patient satisfaction. The aim of this study was to identify predictors of prolonged hospital LOS after surgery for Meyerding grade 2 spondylolisthesis using a multicenter prospectively collected registry. METHODS: The prospectively collected Spine CORe™ Quality Outcomes Database (QOD) study group cohort, which consisted of 328 patients from 14 sites, was used to identify all patients who underwent single-stage lumbar fusion for Meyerding grade 2 lumbar spondylolisthesis. Prolonged LOS was defined as ≥ 4 days (75th percentile). An array of demographic, comorbidity, and perioperative factors known to impact LOS were collected for each patient. Bivariate tests, including the chi-square goodness of fit and independent t-test, were used to identify variables associated with prolonged LOS. Multivariable logistic regression analysis was conducted to determine independent predictors of prolonged LOS. RESULTS: The QOD cohort comprised 328 patients with a follow-up rate of > 80%. After excluding patients with an anterior or lateral surgical approach and missing LOS data, the final cohort included 268 patients, of whom 52 (19.4%) experienced a prolonged LOS. In the univariate analysis, older age, dependent ambulation, insurance status, depression, greater estimated blood loss, longer operative duration, multilevel fusion (2 or more levels), perioperative complications (e.g., incidental durotomy and urinary tract infection), and nonhome discharge were associated with prolonged LOS. In the adjusted model, multilevel arthrodesis independently increased the odds of prolonged LOS (OR 2.11, 95% CI 1.07-4.18; p = 0.03), whereas private insurance (vs Medicare/Medicaid/government) was associated with lower odds (OR 0.42, 95% CI 0.20-0.87; p = 0.02). Patient-reported outcomes at 60 months did not differ between the groups with and without prolonged LOS. CONCLUSIONS: In this multicenter Spine CORe™ QOD study, multilevel lumbar fusion and noncommercial insurance were the principal independent predictors of prolonged LOS after surgery for grade 2 spondylolisthesis. These findings are valuable for patient informed consent, as well as to identify higher-risk patients who could benefit from earlier inpatient resource allocation (social work and counseling) to facilitate timely discharge.