Patient- and hospital-related risk factors for non-routine discharge after lumbar decompression and fusion for spondylolisthesis

Objective: In various spinal surgeries, non-routine discharges have been associated with inferior outcomes. However, there exists a paucity of data regarding the relationship between non-routine discharge and quality of care among patients with spondylolisthesis. The aim of this study was to identify independent predictors for non-routine discharge following spinal decompression and fusion for lumbar spondylolisthesis. Methods: A retrospective cohort study was performed using the American College of Surgeons (ACS) National Surgical Quality Improvement Program (NSQIP) database from 2010 through 2016. Adult patients (≥18 years old) who underwent spinal decompression and fusion for lumbar spondylolisthesis were identified using ICD-9-CM diagnosis and CPT procedural coding systems. The study population was divided into two cohorts based on discharge disposition: routine (RD) and non-routine discharge (NRD). Patient demographics, comorbidities, adverse events, LOS, reoperation, and readmission were assessed. A multivariate logistic regression model was used to identify the independent predictors of non-home discharge and 30-day unplanned readmission. Results: A total of 5252 patients were identified, of which 4316 (82.2%) had a RD and 936 (18.8%) had a NRD. The NRD cohort tended to be older (p < 0.001) and have a higher BMI (p < 0.001). Patients who experienced a NRD had a longer LOS (NRD: 4.7 ± 3.7 days vs RD: 3.1 ± 2.0 days, p < 0.001), a higher proportion of adverse events (p < 0.001), higher rates of reoperation (p = 0.005) and unplanned 30-day readmission rates (p < 0.001). On multivariate regression analysis, age [OR: 1.08, 95% CI (1.06–1.10), p < 0.001], female sex [OR: 2.01, 95% (1.51–2.69), p < 0.001], non-Hispanic Black race/ethnicity [OR: 2.10, 95% CI (1.36–3.24), p = 0.001], BMI [OR: 1.03, 95% CI (1.01–1.05), p = 0.007], dependent functional status [OR: 3.33, 95% CI (1.59 – 6.99), p = 0.001], malnourishment [OR: 2.14, 95% CI (1.27–3.62), p = 0.005], and LOS [OR: 1.26, 95% CI (1.18–1.33), p < 0.001] were all independent predictors for NRD. However, NRD did not independently predict an unplanned 30-day readmission on multivariate analysis. Conclusion: In our study we found that on univariate analysis NRD was associated with increased adverse events, length of stay and 30-day unplanned readmission. When controlling for patient- and hospital-related factors, we found that female sex, non-Hispanic Black race, BMI, dependent functional status, malnourishment and longer LOS were independently associated with NRD. However, NRD did not independently predict an unplanned 30-day readmission.