Trends in Ambulatory and Emergency Room Visits for Inflammatory Bowel Diseases in the United States: 1994-2005

OBJECTIVES: Inflammatory bowel diseases (IBDs) require frequent healthcare encounters. Analysis of trends in disease burden is important to study the changing epidemiology of disease. The aim of our study was to examine national trends in IBD-related visits in ambulatory and emergency room (ER) settings. METHODS: We used data from the National Ambulatory Medical Care Survey (NAMCS) and National Hospital Ambulatory Medical Care Survey (NHAMCS) using the International Classification of Diseases, 9th Revision, Clinical Modification codes to identify IBD-related visits. The annualized number of visits was examined in 3-year time periods from 1994 to 2005. We compared the demographic distribution of the inpatient, outpatient, and ER IBD cohorts. RESULTS: There were an estimated 1.1 million (95% confidence interval (CI): 0.9-1.4 million) annual IBD-related visits during the period 1994-1996 increasing to 1.8 million (95% CI: 1.4-2.2 million) visits during 2003-2005 (+ 55%). Correspondingly, there were 28,752 estimated annual ER visits (95% CI: 16,299-41,206) related to IBD during 1994-1996 increasing to 76,374 annual visits (95% CI: 42,498-112,257) during 2003-2005 (+ 165%). The proportion of outpatient visits by patients older than 50 years increased from 34.1 to 52.0% (P < 0.0001). Use of corticosteroids decreased from 26.5% of visits to 14.5% (P < 0.0001), with a corresponding rise in immunomodulator/biologic use (2.6-13.8%, P < 0.0001). Younger, self-pay patients and those with Crohn's disease were over-represented in the ER IBD cohort compared with inpatients or outpatients. CONCLUSIONS: There has been an increase in IBD-related ambulatory and ER visits from 1994 to 2005. There is a need for research examining the reasons for the disproportionate representation of certain demographic groups in the ER setting.