Jonathan Nguyen, MD1, Julia Wei, MPH2, Nirmala Ramalingam, MPP1, Benjamin Hassid, MD1
1Kaiser Permanente Medical Center, Oakland, CA; 2Kaiser Permanete, Oakland, CA
Introduction: The prevalence of inflammatory bowel disease (IBD, ulcerative colitis (UC) and Crohn’s disease (CD)) has been estimated to be approximately 400-600 per 100,000 persons in the United States3, but this relies on data skewed heavily towards Caucasian populations. Previous studies have suggested that IBD prevalence in Asia is much lower, around 30-60 per 100,0007. A recent study highlighted higher rates and more extensive UC in migrant groups than in their home countries5. However, the overall trend with IBD being more prevalent in Caucasians compared to Asians has been shown previously. One caveat to this is in South Asians, who have a higher incidence and prevalence of UC compared to the indigenous population of the UK5. In this study we seek to further breakdown the prevalence of IBD among Asian subgroups in a Northern California integrated health care delivery system.
Methods: Adults aged 18 years and older diagnosed with IBD between 1/1/2014-12/31/2014 were identified with ICD-9 diagnosis codes for UC (556.x) and CD (555.x). We calculated overall period prevalence of IBD, UC and CD by race/ethnicity, including Asian subtypes.
Results: Among 7,766 Kaiser Permanente Northern California (KPNC) members with IBD, the prevalence of IBD was higher in Caucasians compared to Asians (377 vs 125 per 100,000, p < 0.01 Table 1). However, when Asians were further subclassified, the period prevalence among South Asians was significantly higher than not only the other Asian subgroups, but also the Caucasian group (504 vs 377 per 100,000). Breaking up IBD into CD and UC, the period prevalence among Asians continued to be significantly lower than Caucasians (Table 2). However, among South Asians the prevalence of UC is again higher than that of Caucasians (417 vs 208 per 100,000). Interestingly, the prevalence of CD is less among South Asians compared to Caucasians (87 vs 169 per 100,000).
Discussion: Our data from a diverse patient population in Northern California show an overall lower prevalence of IBD in Asian compared to Caucasian patients overall but a higher prevalence among South Asians. Our data is consistent with prior Canadian and UK studies5. Most American studies combine South Asians into the Asian category, which shows a deceptively decreased prevalence compared to the Caucasian population. Further studies are needed to understand the etiology of this finding and seek to further explore the differences among Asian subpopulations.
Citation: Jonathan Nguyen, MD; Julia Wei, MPH; Nirmala Ramalingam, MPP; Benjamin Hassid, MD. P0468 - PREVALENCE OF IBD AMONG ASIAN SUBGROUPS IN A NORTHERN CALIFORNIA MANAGED CARE ORGANIZATION. Program No. P0468. ACG 2019 Annual Scientific Meeting Abstracts. San Antonio, Texas: American College of Gastroenterology.