Increase in National Inpatient Admissions for Inflammatory Bowel Disease: 2000-2014

Introduction: The prevalence of Inflammatory Bowel Disease (IBD) in the US has increased since the late 1990s. This study investigates the trend in volume of hospital admissions due to IBD between 2000 and 2014, with respect to patient payer status and patient income. Methods: The National Inpatient Sample (NIS) database was queried for inpatient admissions due to IBD between 2000 and 2014 using ICD-9-CM codes inclusive of 555.0 and 556.0 and their respective subcodes. “Low income” is living in a ZIP Code for the lowest earning quartile of Americans for that year. Patients with “other” and “missing” payer statuses were omitted from this study. Results: Between 2000 and 2014, the national volume of admissions for IBD increase by 39.5% (71,157 to 99,265). Based on patient insurance status, this increase appears to be driven by a 207% increase of admissions amongst Medicaid beneficiaries(6,341 to 19,469). The number of admissions for Medicare, Privately Insured and Uninsured patients increased by 37.4%, 11.5% and 88.6%, respectively (15,890 to 21,830, 42,915 to 47,850, and 3,522 to 6,645) (Figure 1A). Interestingly, based on patient income, this increase appears to be driven by a 546% increase in admissions for low-income patients (from 3795 to 24,520). Whereas the number of admissions for not low-income patients only increased by 10.1% (from 66,204 to 72,905) (Figure 1B). Conclusion: There has been an increase in IBD related inpatient admissions, an observation that appears to be driven mostly by Medicaid beneficiaries and low-income patients. While this study does not specify, this may be because of increased incidence, increased diagnostic recognition or increased need for inpatient admission amongst these populations. Considering that utilization and costs of biologics have increased, this study raises the concern whether patients who are on Medicaid or who qualify as low-income have equitable access considering the disproportionately increasing volume of inpatient admission for IBD.Figure 1.: Figure 1A: Annual number of IBD hospital admissions stratified by patient payer Figure 1B: Annual number of IBD hospital admissions stratified by patient income.