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.