93. Weekend admission increases risk of readmissions following elective thoracolumbar spinal fusion

Abstract

<h3>BACKGROUND CONTEXT</h3> Previous studies have investigated the impact of weekend admissions on patient outcomes for both emergency and elective procedures with conflicting results. These studies have utilized various outcome measures to assess the "weekend effect," including hospital readmission rates. <h3>PURPOSE</h3> The purpose of this study is to ascertain whether weekend admissions negatively impact patient outcomes as measured by hospital readmission rates for patients undergoing elective thoracolumbar spinal fusion surgery. <h3>STUDY DESIGN/SETTING</h3> This is a retrospective database study conducted using the 2016-2018 National Readmission Database (NRD), a database tracking discharge data from approximately 60% of all hospitalizations in the United States. Patient characteristics were obtained from the NRD, including initial admission day (weekday or weekend), readmission status, demographic information (sex and age), payer type, preoperative comorbidities, postoperative complications and discharge status. <h3>PATIENT SAMPLE</h3> Adult patients who underwent elective thoracolumbar spinal fusion were identified using ICD-9-CM and ICD-10-CM procedure codes. A total of 177,847 patients undergoing elective thoracolumbar spinal fusion surgery were identified, with 176,842 in the weekday admission cohort and 1,005 in the weekend admission cohort. <h3>OUTCOME MEASURES</h3> Primary outcome measures include 30-day and 90-day readmission rates for both cohorts. Differences in demographic characteristics, comorbidities, postoperative complications, and discharge status between the two cohorts are also reported. <h3>METHODS</h3> SciPy version 1.6.1 was used for all statistical analyses conducted. Univariate logistic regression was used to analyze the association between weekday or weekend admission status and 30-day or 90-day readmission rates. Multivariate logistic regression was used to adjust the regression analysis for sex, age, Medicare or Medicaid status, and comorbidity status. Preoperative and postoperative cohort characteristics were compared using univariate regression. <h3>RESULTS</h3> The 30-day readmission rate was 4.70% for the weekday cohort and 8.96% for the weekend cohort, and the 90-day readmission rate was 7.79% for the weekday cohort and 14.50% for the weekend cohort. Thirty-day readmissions were significantly greater for the weekend cohort after adjusting for sex, age, Medicare or Medicaid status, and comorbidity status (OR 2.00, 95% CI: 1.60-2.48; p <0.001), and 90-day readmissions were also greater for the weekend cohort after adjustment (OR 2.01, 95% CI: 1.68-2.40, p <0.001).Weekend admission patients are more likely to be male and have increased incidence of obesity (p <0.05), increased prevalence of DVT and postoperative infection (p <0.05),), and increased likelihood of being discharged against medical advice and discharged to skilled nursing facilities, intermediate care facilities, and other types of facilities (p <0.05). <h3>CONCLUSIONS</h3> Patients undergoing elective thoracolumbar spinal fusion surgery who are initially admitted on weekends are more likely to experience hospital readmission. The postoperative factors that differed the most between weekday and weekend admission patients were incidence of DVT and postoperative infection as well as nonroutine discharge status, including discharges against medical advice and discharges to various facilities. Therefore, these factors are potential areas of focus for reducing the impact of the "weekend effect" and improving outcomes for elective thoracolumbar spinal fusion. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.