Prevalence of extraintestinal manifestations in Korean inflammatory bowel disease patients

RESEARCH ARTICLE Prevalence of extraintestinal manifestations in Korean inflammatory bowel disease patients Bo Ram Yang1, Nam-Kyong Choi2, Mi-Sook Kim1,3, Jaeyoung Chun4, Sang Hyun Joo5, Hyesung Kim6, Joongyub Lee7,8* a1111111111 a1111111111 a1111111111 a1111111111 a1111111111 1 Medical Research Collaborating Center, Seoul National University Hospital, Seoul, Republic of Korea, 2 Department of Health Convergence, Ewha Womans University, Seoul, Republic of Korea, 3 Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea, 4 Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul, Republic of Korea, 5 Division of Rheumatology, Department of Internal Medicine, Seoul National University Hospital, Seoul, Republic of Korea, 6 Medical Affairs, Janssen Korea, Seoul, Republic of Korea, 7 School of Medicine, Inha University, Incheon, Republic of Korea, 8 Department of Prevention and Management, Inha University Hospital, Incheon, Republic of Korea * OPEN ACCESS Citation: Yang BR, Choi N-K, Kim M-S, Chun J, Joo SH, Kim H, et al. (2018) Prevalence of extraintestinal manifestations in Korean inflammatory bowel disease patients. PLoS ONE 13 (7): e0200363. https://doi.org/10.1371/journal. pone.0200363 Editor: Gang Liu, Institute of Subtropical Agriculture, Chinese Academy of Sciences, CHINA Abstract Background The prevalence of inflammatory bowel disease (IBD) in South Korea is increasing. Although extraintestinal manifestations (EIMs) are an important factor in the clinical outcomes of IBD patients, EIMs have not yet been investigated in Korea. Thus, we conducted a cross-sectional study to assess the prevalence of EIMs in Korean IBD patients. Received: February 12, 2018 Accepted: June 25, 2018 Published: July 10, 2018 Copyright: © 2018 Yang et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Data Availability Statement: The National Health Insurance Database and the National Patient Sample data (HIRA-NPS database) were third party data owned by the National Health Insurance Corporation (NHIC), and Health Insurance Review and Assessment Service (HIRA) Korea, respectively. Interested researchers can contact NHIC to access the data in the following ways: Tel: 82-33-736-2469 (Big data operation room, NHIC), Web: https://nhiss.nhis.or.kr/bd/ab/bdaba000eng. do. The HIRA-NPS database can be provided after making a request via the Healthcare Bigdata Hub’ Methods The 2014 claims data from the National Health Insurance System (NHIS) of Korea were used. IBD patients were identified by codes for Crohn disease (CD) and ulcerative colitis (UC) in the NHIS registration system for rare or intractable diseases. International Classification of Diseases, Tenth Edition codes were used to identify EIM cases. To estimate the prevalence of EIMs in the general population of Korea, we used national sample data. Standardized prevalence ratios (SPRs) were calculated to compare the prevalence rates of EIMs among IBD patients to those among the general population of Korea. Results A total of 13,925 CD patients and 29,356 UC patients were identified. CD and UC patients were different in terms of demographics and utilization of medication. Among the 17 EIMs investigated, pyoderma gangrenosum, osteomalacia, Sweet syndrome, and scleritis were observed in very few patients. The SPRs were greater than 1 for all EIMs. Aphthous stomatitis, rheumatoid arthritis, and osteoporosis were highly prevalent in both CD and UC patients, but the SPRs of the EIMs were not high. PLOS ONE | https://doi.org/10.1371/journal.pone.0200363 July 10, 2018 1 / 13 Prevalence of extraintestinal manifestations in inflammatory bowel disease patients site (http://opendata.hira.or.kr/op/opc/ selectPatDataAplInfoView.do) operated by the HIRA. The authors do not have any special access privileges to these data. Funding: This study was funded by Janssen Korea (http://www.janssen.com/korea/company), RRA16010 (JL). The funder provided support in the form of salaries for HK, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing interests: Employment by Janssen (HK) does not alter our adherence to PLOS ONE policies on sharing data and materials. Conclusion The study confirmed that EIMs are more prevalent among IBD patients than among the general population of Korea. The prevalence of EIMs in IBD patients suggests the need for greater attention and effort in clinical practice. Introduction Inflammatory bowel disease (IBD) includes Crohn disease (CD) and ulcerative colitis (UC). IBD is a systemic inflammatory disease that can affect all parts of the body, meaning that it can have extraintestinal manifestations (EIMs). EIMs occur most frequently in the joints, skin, the hepatobiliary system, and the eye [1–4]. It has been reported that 6%-47% of IBD patients experience EIMs, with considerable variation across studies [5–8]. Approximately a quarter of EIMs are first identified before the onset of IBD, and the remaining 75% are diagnosed after the diagnosis of IBD. Within 30 years after the diagnosis of IBD, about half of patients experience at least 1 EIM [1]. It has been reported that as many as 25% of patients experience multiple EIMs [9]. Recent studies in Korea have shown a significant increase in the prevalence of IBD compared to the past [10]. Nonetheless, the 5-year survival rate of IBD was found to be 96.6%, which is similar to the rate reported in previous studies in Korea and Japan, and higher than the rates reported for Western countries [11–13]. Since EIMs have a major impact on the quality of life of IBD patients, it is necessary to establish the prevalence of EIMs in IBD patients in Korea, considering the recent increase in IBD. However, epidemiological data regarding EIMs in Korean IBD patients are scarce, and nationwide data for EIMs in Korea have not been obtained. The purpose of this study was to analyze the prevalence of EIMs in Korean IBD patients using national health insurance data. Materials and methods This cross-sectional study was conducted to evaluate the prevalence of EIMs in IBD patients in comparison to the corresponding rates in the general population of Korea. Data source We used the 2014 National Health Insurance Database (NHID) of Korea. The National Health Insurance system is a mandatory health insurance program that covers all Korean residents, so the NHID can play a role as infrastructure for epidemiological studies representing the whole population [14]. The data resource profile of NHID has been published elsewhere [15]. The NHID can be used after approval by the review committee of the National Health Insuran (...truncated)