Effects of preoperative nutritional status on complications and readmissions after posterior lumbar decompression and fusion for spondylolisthesis: A propensity-score analysis

Introduction: Malnutrition, common in the elderly, may adversely affect healthcare outcomes. In spine surgery, malnutrition is associated with higher rates of perioperative complications, unplanned readmission, and prolonged length of stay (LOS). The aim of this study was to determine the effect of malnutrition on adverse events (AEs), unplanned readmission, and LOS in patients undergoing spine surgery for spondylolisthesis. Methods: A retrospective cohort study was performed using the American College of Surgeons National Surgical Quality Improvement Program database from 2010 to 2016. Adult patients who underwent posterior decompression or fusion for spondylolisthesis were identified using the ICD-9-CM coding systems. Patients were divided into two cohorts based on preoperative serum albumin levels. propensity-score (PS) matching was used to create an age- and sex-matched Nourished cohort. Patient demographics, comorbidities, LOS, and postoperative complications were collected. Multivariate logistic regression analysis was performed to identify predictors of prolonged LOS, unplanned readmission, and AEs. Results: Of the 2196 patients identified, 4.5% were malnourished. Patients in the Malnourished cohort were found to have significantly longer average LOS (Malnourished: 4.51 ± 3.1 days vs PS-Matched Not Nourished: 3.7 ± 3.7, p = 0.002), higher rates of AEs (Malnourished: 14.3% vs PS-Matched Nourished: 5.8%, p = 0.007), reoperation (Malnourished: 8.4% vs PS-Matched Nourished: 3.2%, p = 0.026), and unplanned readmission (Malnourished: 15.3% vs PS-Matched Nourished: 6.1%, p = 0.003). On multivariate analysis considering only preoperative data, malnutrition was a significant independent predictor of AEs [OR: 2.13, CI (1.02, 4.46), p = 0.045]. However, after correcting for the occurrence of AEs, malnutrition was not associated with total LOS [aRR: 0.29, CI (−0.37, 0.95), p = 0.392] or 30-day unplanned readmissions [aOR: 2.24, CI (0.89, 5.60), p = 0.086]. Conclusion: Our study found that malnourished patients undergoing lumbar fusion for spondylolisthesis have significantly higher rates of AEs, unplanned readmission, and prolonged LOS than nourished patients. Further studies are necessary to corroborate our findings.