115. Preoperative factors associated with outpatient lumbar decompression surgery

Abstract

BACKGROUND CONTEXT With spine procedures moving toward the outpatient setting and evolving payment models, improved risk-stratification and patient selection will be necessary to increase patient safety, improve clinical outcomes, enhance cost efficiency and reimbursements. Therefore, the identification of patient characteristics associated with successful outpatient lumbar decompression surgery is paramount. PURPOSE The purpose of this study was to determine independent preoperative factors associated with patients undergoing outpatient lumbar decompression surgery. STUDY DESIGN/SETTING Retrospective cohort study. PATIENT SAMPLE Patients who underwent 1- to 4- level lumbar decompression surgery at a single, academic medical center were retrospectively identified. OUTCOME MEASURES Independent predictors including patient demographics, insurance status, levels decompressed, comorbidities, preoperative patient-reported outcome measures (PROMs) and readmission rates. METHODS Outpatient surgery was defined as a patient length of stay of either 0 or 1 day. Inpatient surgery was defined as a patient length of stay of 2 or more days. Univariate analysis was used to compare differences among patient demographics, comorbidities, preoperative PROMs, and readmission events within a 30- or 90-day time period. Multivariate logistic regression analysis was used to determine independent preoperative factors associated with an outpatient procedure status for patients after lumbar decompression surgery. RESULTS Comparison of baseline patient demographics demonstrated a significant difference between outpatient and inpatient surgery cohorts for age greater than 75 (p<0.001), gender (p<0.039), BMI greater than 35 (p<0.010), ASA (p<0.001), insurance status (p<0.001), levels decompressed (p<0.001), history of diabetes mellitus (DM) (p<0.001), preoperative VAS leg score (p=0.017), and readmission events (p<0.001). Fewer patients were readmitted after an outpatient procedure (3.5%); however, more patients in this group were found to return to the ER after discharge (6.3%). Multivariate logistic regression models demonstrated that age >75 (OR: 0.58 [0.38,0.89], p<0.012), female gender (OR: 1.42 [1.04-1.93], p=0.03), ASA class 2 (OR: 0.42 [0.27-0.67], p<0.001) and class 3 (OR: 0.21 [0.12-0.37], p<0.001), private/other insurance status (OR: 1.91 [1.37-2.66], p<0.001), history of DM (OR: 0.66 [0.45-0.95], p=0.028), and preoperative VAS leg (OR: 0.96 [0.92-1.00], p=0.035) were found to be significant independent preoperative factors associated with patients undergoing outpatient lumbar decompression surgery (AUC: 0.701). CONCLUSIONS Overall, our results suggest that patients with successful outpatient lumbar decompression surgery generally fit the following criteria: under the age of 75, females, an ASA score of 1, private/other insurance, one-level decompressions, and exhibit lower preoperative VAS leg scores. These characteristics, in addition to not having a history of DM, were found to be significant predictors for successful outpatient lumbar decompression surgery. Patients with outpatient surgical intervention had less readmissions; however, they returned to the ER more often than patients who had an inpatient procedure. Defining independent preoperative factors associated with successful outpatient lumbar spine surgery will allow for enhanced risk-stratification, improved outcomes and reimbursements. Further studies are needed to validate these findings and develop computer-assisted algorithms that can help physicians predict patient discharge disposition and minimize patient risks and resource utilization. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs. With spine procedures moving toward the outpatient setting and evolving payment models, improved risk-stratification and patient selection will be necessary to increase patient safety, improve clinical outcomes, enhance cost efficiency and reimbursements. Therefore, the identification of patient characteristics associated with successful outpatient lumbar decompression surgery is paramount. The purpose of this study was to determine independent preoperative factors associated with patients undergoing outpatient lumbar decompression surgery. Retrospective cohort study. Patients who underwent 1- to 4- level lumbar decompression surgery at a single, academic medical center were retrospectively identified. Independent predictors including patient demographics, insurance status, levels decompressed, comorbidities, preoperative patient-reported outcome measures (PROMs) and readmission rates. Outpatient surgery was defined as a patient length of stay of either 0 or 1 day. Inpatient surgery was defined as a patient length of stay of 2 or more days. Univariate analysis was used to compare differences among patient demographics, comorbidities, preoperative PROMs, and readmission events within a 30- or 90-day time period. Multivariate logistic regression analysis was used to determine independent preoperative factors associated with an outpatient procedure status for patients after lumbar decompression surgery. Comparison of baseline patient demographics demonstrated a significant difference between outpatient and inpatient surgery cohorts for age greater than 75 (p<0.001), gender (p<0.039), BMI greater than 35 (p<0.010), ASA (p<0.001), insurance status (p<0.001), levels decompressed (p<0.001), history of diabetes mellitus (DM) (p<0.001), preoperative VAS leg score (p=0.017), and readmission events (p<0.001). Fewer patients were readmitted after an outpatient procedure (3.5%); however, more patients in this group were found to return to the ER after discharge (6.3%). Multivariate logistic regression models demonstrated that age >75 (OR: 0.58 [0.38,0.89], p<0.012), female gender (OR: 1.42 [1.04-1.93], p=0.03), ASA class 2 (OR: 0.42 [0.27-0.67], p<0.001) and class 3 (OR: 0.21 [0.12-0.37], p<0.001), private/other insurance status (OR: 1.91 [1.37-2.66], p<0.001), history of DM (OR: 0.66 [0.45-0.95], p=0.028), and preoperative VAS leg (OR: 0.96 [0.92-1.00], p=0.035) were found to be significant independent preoperative factors associated with patients undergoing outpatient lumbar decompression surgery (AUC: 0.701). Overall, our results suggest that patients with successful outpatient lumbar decompression surgery generally fit the following criteria: under the age of 75, females, an ASA score of 1, private/other insurance, one-level decompressions, and exhibit lower preoperative VAS leg scores. These characteristics, in addition to not having a history of DM, were found to be significant predictors for successful outpatient lumbar decompression surgery. Patients with outpatient surgical intervention had less readmissions; however, they returned to the ER more often than patients who had an inpatient procedure. Defining independent preoperative factors associated with successful outpatient lumbar spine surgery will allow for enhanced risk-stratification, improved outcomes and reimbursements. Further studies are needed to validate these findings and develop computer-assisted algorithms that can help physicians predict patient discharge disposition and minimize patient risks and resource utilization.