Characteristics of Anemia in Inflammatory Bowel Disease (IBD) Patients and Their Impact on Disease Activity and Health Care Utilization at a Tertiary Referral IBD Center

Abstract

Introduction: Anemia is one of the most common extra-intestinal complications of inflammatory bowel disease (IBD). European literature illustrates that anemic IBD patients are likely to develop more severe disease. However, United States data demonstrates limited literature in this regard. We aimed to assess the IBD characteristics, disease activity, and health care utilization between IBD patients with and without anemia presenting to an urban tertiary referral IBD center. Methods: Patients with IBD presenting to an inner-city tertiary referral center from 2008-2018 were included in this retrospective study. Inpatient and outpatient charts were individually reviewed and demographic and clinical data was collected, including laboratory data, endoscopy reports, imaging, surgery reports, and patterns of IBD medication use. ESR, CRP, endoscopic evaluation, and imaging reports at the time when Hb levels were the lowest was captured. Anemia and its severity was defined according to WHO criteria: men with Hb <13 g/dL, in non-pregnant women <12 g/dL, in pregnant women <11 g/dL. Differences between the two groups were evaluated using the Mann-Whitney U test for non parametric continuous data and chi-square test for categorical variables. Results: A total of 265 patients were included in the analysis. Anemia was noted in 138 patients (52%) at one point during their follow up period (54% with CD vs 48% with UC, p 0.34). IBD demographics, disease activity, and health care utilization were compared between anemic and non-anemic patients with IBD (Table 1). Anemic patients were noted to have more active disease on endoscopy or imaging within 1 year of their lowest hemoglobin level, compared to non-anemic patients (79% vs 42%, p<0.0001). In addition, anemic patients had a higher median ESR and CRP level than non-anemic patients (Table 1). Anemic patients also required higher health care utilization compared to non-anemic patients with IBD; this included greater usage of biologics and immunomodulators, more surgeries for IBD, and more frequent hospital visits (Table 1). Of note, iron replacement therapy was administered in only 43.4% of patients with IBD. Conclusion: Anemia has a high period prevalence in IBD patients followed at our tertiary referral center. While anemia is associated with an increase in disease activity and higher health care utilization, it is evidently undertreated in current practice. Our study indicates anemia in IBD patients requires close attention and should not be overlooked.699 Figure 1. Patient demographics, disease characteristics, and healthcare utilization statistics