P-024 YI The Incidence of Crohn’s Disease and Rate of Early Surgery in the U.S. Military Health Care System

Abstract

Surgery is often required to treat complications of Crohn's Disease (CD) such as medically refractory inflammation, fistulas or strictures. Surgical intervention, especially early in the disease course, may be decreasing with the advent of more effective medical therapy for CD as gastroenterologists rely more readily on immunosuppressive strategies before referring for surgery. The US Military Health System (MHS) has a diverse population of patients with equal access, and the direct care military treatment facilities (MTF) utilize the same electronic medical record (EMR) nationwide. The aim of this study was to calculate the incidence of CD in a nationwide military population and to further characterize the CD population, while also assessing outcomes such as surgery, hospitalization and emergency room visits during the first 2 years of disease. Using the EMR and healthcare claims databases under the MHS Data Repository (MDR), the total number of new diagnoses of CD were examined from 2009 to 2012. The data collected were derived from a nationwide network of military treatment facilities and included a total study population of 3.2 million. For each new diagnosis of CD, demographic variables, basic laboratory data, other chronic comorbidities, and serious associated diseases or complications were analyzed. Outcomes such as ER visits, admissions, surgeries and deaths were also recorded up to 2 years from the time of diagnosis. Seven hundred and three new diagnoses of Crohn’s disease were identified. The average annual incidence of CD was 7.3 per 100,000 patients per year. Fifty-two percent of patients were male. Fifty-three percent of patients were under the age of 35. Within two years of diagnosis, 9% patients underwent surgery for CD with an average annual rate of 1 surgery for every 11 new diagnoses per year. Within two years of diagnosis, 38% of patients were admitted to the hospital (71% of these admissions were directly related to CD). Seven percent of patients were admitted to the ICU and 64% were seen in the ER. Two percent required total parenteral nutrition. No patients died. Three percent of patients were diagnosed with Clostridium difficile colitis. Two percent of patients had a pulmonary embolism or deep vein thrombosis. Our study shows a similar incidence rate of CD compared to an earlier large population study in the US (7.3/100,000 compared to 7.9/100,000), which suggests a stable incidence over time. The early surgery rate in our study is lower than that found in other published studies. This may correlate with a trend of decreasing reliance on surgery in the era of biologic medications. Our hospitalization rate is slightly higher than that reported in an earlier study in Olmsted County (32% at 1 year), but lower than that reported in an earlier study from Denmark (83% at 1 year) which indicates that treatments are more effective, but the disease still portends significant morbidity and utility of healthcare resources. Further research may help further elucidate the effects that the biologic agents have had in improving outcomes and reducing surgery in non-referral centers.