P781 Defining the economic burden of venous thromboembolism after surgery for inflammatory bowel disease in the USA: a national inpatient sample study

Abstract Background The economic burden associated with VTE after surgery for IBD has not been reported. Therefore, we aimed to use a large national database to define the rate of post-operative VTE, and VTE-associated healthcare costs. Methods A retrospective, cross-sectional analysis was performed using National Inpatient Sample data from 2010 to 2014. The International Classification of Disease 9th ed. diagnostic and procedure codes were used to identify patients with primary diagnosis of Crohn’s disease (CD) or ulcerative colitis (UC) who underwent major surgery. VTE included any extremity DVT, pulmonary embolism, portomesenteric venous thrombosis, and cerebral venous sinus thrombosis. The national VTE rate and VTE associated costs were estimated. Uni- and multi-variate logistic regression models were used to compare patient and hospital characteristics and outcomes between VTE and non-VTE groups. The total average direct costs in dollars were compared between groups using linear regression, in dollars, extrapolated to the national population. Results Any VTE was identified in 1,656 (5.3%) out of a total of 31,242 patients. On univariate analysis, older age, white race, higher Elixhauser comorbidity score, UC diagnosis, hospital transfer prior to surgery, larger bed size and urban teaching hospital were associated with VTE; conversely, elective surgery, laparoscopy and colectomy (compared with proctectomy and >1 type of resection) were associated with lower risk of VTE. On multi-variate analysis age, Elixhauser score, resection type, transfer status, hospital bed size, location and teaching status of hospital were independently associated with VTE. Proctectomy and >1 type of resection were independent factors associated with increased risk of VTE compared with colectomy alone (OR 1.5, 95% CI 1.3–1.9; OR 1.4, 95% CI 1.2–1.6, respectively; both p < 0.001). In terms of outcomes, patients who developed VTE had an increased length of stay (11.3 vs. 7.6 days; p < 0.001) and higher inpatient mortality (5.4% vs. 3.7%; OR 1.5, 95% CI 1.2–1.8; p < 0.001) compared with the non-VTE cohort. Direct costs were significantly higher in the VTE group, with an addition cost of $14,939 (95% CI $12369–$17510, p < 0.001) per admission. After adjusting for clinically relevant covariates, the cost difference was $10,507 (95% CI $9649 – $11365, p < 0.001). Nationwide, the additional cost of VTE was estimated at $17 031847 annually. Conclusions VTE after abdominopelvic surgery