S813 Venous Thromboembolism Rates Among Patients Hospitalized for Inflammatory Bowel Disease Exacerbation: A Time Trend Analysis of the National Inpatient Sample

Abstract

Introduction: Inflammatory bowel disease (IBD) flare increases risk of venous thromboembolism (VTE) events, especially during hospitalization. Guidelines, support the use of VTE prophylaxis for these patients, but it is unclear if this has impacted rates of VTE. Our goal was to assess time trends of VTE rates among IBD admissions. Methods: Patients hospitalized from 2007 to 2019 were identified in the National Inpatient Sample (NIS) by International Classification of Diseases (ICD), 9th and 10th Revision codes. Patients with IBD flare were selected by either a) a primary diagnosis of Crohn’s disease (CD) or Ulcerative colitis (UC) or b) a secondary diagnosis of CD or UC with a primary diagnosis of a gastrointestinal manifestations of IBD: abdominal pain, anemia, malnutrition, or dehydration. Hospitalizations for VTE were identified by those with a primary or secondary diagnosis of VTE. Patients with chronic thrombosis or prior VTE were excluded. Incidence of VTE was assessed by disease type (CD vs. UC) and by racial/ethnic identification: white, black, Hispanic, Asian or Pacific Islander, Native American, other. Cochran-Armitage trend tests were used for binary variables while trends for variables with reported mean averages used linear regression. The Rao-Scott design-adjusted chi-square test was used to evaluate the association between binary variables and the diagnosis of IBD in patients with VTE. Results: 131,541 weighted cases were admitted for an IBD flare complicated by VTE; 73,530 had CD and 58,011 had UC, Table. VTE prevalence was higher among patients with UC compared to CD, 42.6 vs. 30.7 per 1,000 hospitalizations, respectively. Over the study period, the rates of VTE in IBD hospitalizations increased, from 3.58% to 4.62% for UC (p< 0.0001) and from 2.22% to 3.66% for CD (p< 0.0001), Figure 1a. Black patients with IBD were found to be at higher risk of VTE (aOR 1.075, p=0.002), while Hispanic and Asian / Pacific Islanders had lower risk for developing VTE when compared to Whites (aOR 0.873 and 0.658, respectively; p< 0.0001). Aside from Hispanic and Native American UC patients, all races and ethnicities had increasing trends of VTE during the study period, Figure 1b, 1c. Conclusion: IBD admissions complicated by VTE have significantly increased. Though increasing awareness of VTE with IBD flare may have resulted in additional diagnoses, the study findings suggest that current VTE prophylaxis, or utilization of VTE prophylaxis, may be inadequate for those hospitalized for IBD flare.Figure 1.: VTE rates as % of total IBD hospitalizations per year. Table 1. - Patient Demographics and Hospital Characteristics of IBD Patients Admitted with VTE Variable Crohn's Disease (n=73,530) Ulcerative Colitis (n=58,011) Age in years [Mean(SD)] 56 (0.16) 60 (0.19) Sex Male 43.7% 50.3% Female 56.3% 49.7% Race* White 81.1% 79.6% Black 12.3% 10.4% Hispanic 3.8% 6.1% Asian / Pacific Islander 0.5% 1.1% Native American 0.4% 0.4% Other 1.9% 2.5% Insurance Type Medicare 48.5% 48.9% Medicaid 12.5% 8.8% Private Insurance 32.7% 36.4% Self-Pay 3.2% 2.8% Other 3.1% 3.1% Hospital Bed Size Small 13.8% 13.5% Medium 25.1% 24.8% Large 61.1% 61.7% Hospital Location/ Type Rural 7.2% 6.1% Urban Nonteaching 28.0% 28.9% Urban Teaching 64.8% 65.0% Charlson Comorbidity Index CCI = 0 36.4% 35.5% CCI = 1 21.8% 21.3% CCI = 2 15.5% 14.7% CCI ≥ 3 26.3% 28.6% Hospitalization Cost $95,500 $110,473 Length of Stay (in mean days) 10.39 11.25 Death (per 1,000 hospitalizations) 41.8 61.4 *There were some charts where race was documented in NIS as unknown.