152. The association of opioid use disorder on perioperative outcomes following lumbar spine laminectomy

Abstract

<h3>BACKGROUND CONTEXT</h3> Opioid use disorder (OUD) is characterized by a pattern of excessive, chronic opioid use leading to problems or distress, which can involve misuse of prescription medication, use of diverted medication or illegally obtained heroin. Studies have reported the prevalence of patients who consume opioids prior to spine surgery to be as high as 72%. Additionally, chronic opioid use and misuse have been linked to several complications following spine surgery. <h3>PURPOSE</h3> The purpose of this study was to determine the association of OUD on perioperative. outcomes following lumbar spine laminectomy. Specifically, we investigated the impact of OUD on: 1) in-hospital LOS, 2) readmission rates, 3) medical complications and 4) health care expenditures. <h3>STUDY DESIGN/SETTING</h3> A retrospective analysis from January 1st, 2005 to March 31st, 2014, of the 100% Medicare Standard Analytical Files (SAF) was performed from the for-fee based PearlDiver (PearlDiver Technologies, Fort Wayne, Indiana, United States) database. <h3>PATIENT SAMPLE</h3> The dataset was initially queried for all patients who underwent lumbar spine laminectomy using the following CPT codes: 63005, 63012, 63017 and 63047. Patients who had OUD were identified using ICD-9 diagnostic codes 304.01, 304.02, 305.51 and 305.52. These procedural and diagnostic codes were utilized as they have been used in previously published studies. A total of 131,635 patients who underwent lumbar spine laminectomy were identified for analysis following the inclusion/exclusion criteria. Of these cases, 3,515 (2.67%) had OUD while 128,120 (97.3%) served as the comparison cohort. <h3>OUTCOME MEASURES</h3> Primary endpoints of the study were to compare in-hospital LOS, readmission rates, medical complications, and healthcare expenditures. Readmission rates and medical complications were those which occurred within the 90-day episode of care interval. Complications analyzed included: acute kidney injuries, cerebrovascular accidents, deep vein thromboses, ileus episodes, myocardial infarctions, pneumoniae, pulmonary emboli, respiratory failures, transfusion of blood products, urinary tract infections, and venous thromboemboli. For health care expenditures, day of surgery and total global 90-day episode of care interval costs were analyzed using reimbursement data. Reimbursements were chosen as they are a more accurate predictor of what providers are paid from the insurance companies. <h3>METHODS</h3> Baseline demographics of the two cohorts were analyzed using Pearson's Chi-Square Analyses or Fischer's Exact test for categorical variables. For continuous variables, Welch's t-tests were used to assess for significance for LOS, healthcare expenditures, and mean Elixhauser Comorbidity Index scores between the two cohorts. A multivariate binomial logistic regression model was constructed to determine the association of OUD on readmission rates and medical complications. The model was adjusted for age, sex, alcohol use disorder, chronic obstructive pulmonary disease (COPD), diabetes mellitus, general anxiety disorder, hyperlipidemia, hypertension, obesity - defined as a body mass index (BMI) greater than 30 kilograms per meter squared (kg/m²) and tobacco use. These comorbid conditions were entered into the regression model as studies have shown OUD to be associated with these comorbid conditions. Incidency and Odds Ratios (OR) are reported. To reduce the probability of a type I error, a Bonferroni-correction was performed, and a p-value less than 0.001 was considered to be statistically significant. <h3>RESULTS</h3> Patients with an OUD undergoing lumbar laminectomy had significantly longer in-hospital LOS (3.68 days vs. 1.13 days, p<0.0001). Readmission rates were significantly higher (14.57% vs 7.39%, OR: 1.73, p < 0.0001) of 90-day medical complications including transfusion of blood products (0.54% vs 0.15%, OR: 5.12, 95% CI: 2.92 -8.48, p < 0.0001), in patients who had an OUD. The study cohort was found to have higher incidence and odds (32.36% vs 9.76%, OR: 3.53, p<0.0001), pneumoniae (6.29% vs 1.23%, OR: 5.23, 95% CI: 3.57 - 4.99, p<0.0001), respiratory failures (0.54% vs 0.12%, OR: 4.07, 95% CI: 2.29 - 6.87, p<0.0001), urinary tract infections (14.54% vs 4.49%, OR: 3.57, 95% CI: 3.19 - 3.97, p<0.0001), acute kidney injuries (4.84% vs 1.36%, OR: 3.31, 95% CI: 2.75 - 3.95, p<0.0001), in addition to other medical complications compared to patients without OUD. Patients with OUD had higher total global 90-day episode of care reimbursement rates ($13,635.81 vs $8,131.20, p<0.0001) compared to their counterparts. <h3>CONCLUSIONS</h3> Patients with an OUD are at a significant risk for increased in-hospital LOS, readmission rates, medical complications and health care expenditures following lumbar decompression surgery. Spine surgeons should seek to identify patients with an OUD and determine strategies to optimize patient care in the perioperative course of lumbar surgery. <h3>FDA DEVICE/DRUG STATUS</h3> This abstract does not discuss or include any applicable devices or drugs.