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Ann Rheum Dis 73:1774-1780 doi:10.1136/annrheumdis-2013-203380
  • Clinical and epidemiological research
  • Extended report

Rheumatoid arthritis increases the risk of deep vein thrombosis and pulmonary thromboembolism: a nationwide cohort study

  1. Chia-Hung Kao7,8
  1. 1Department of Internal Medicine, Taichung Hospital, Department of Health, Executive Yuan, Taichung, Taiwan
  2. 2Department of Healthcare Administration, Central Taiwan University of Science and Technology, Taichung, Taiwan
  3. 3Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan
  4. 4Department of Public Health, China Medical University, Taichung, Taiwan
  5. 5Department of Health Promotion and Health Education, National Taiwan Normal University, Taipei, Taiwan
  6. 6Department of Computer Science and Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan
  7. 7Graduate Institute of Clinical Medicine Science and School of Medicine, College of Medicine, China Medical University, Taichung, Taiwan
  8. 8Department of Nuclear Medicine and PET Center, China Medical University Hospital, Taichung, Taiwan
  1. Correspondence to Dr Chia-Hung Kao, Graduate Institute of Clinical Medicine Science, College of Medicine, China Medical University, No. 2, Yuh-Der Road, Taichung 40447, Taiwan; d10040{at}mail.cmuh.org.tw, dr.kaochiahung{at}gmail.com
  • Received 31 January 2013
  • Revised 15 May 2013
  • Accepted 26 June 2013
  • Published Online First 7 August 2013

Abstract

Objective Studies on the association between rheumatoid arthritis (RA) and deep vein thrombosis (DVT) and pulmonary thromboembolism (PE) are scarce. This study identifies the effects of RA on the risks of developing DVT and PE in a nationwide prospective cohort study.

Methods We studied the entire Taiwan population from 1998 to 2008, with a follow-up period extending to the end of 2010. We identified patients with RA using the catastrophic illness registry of the Taiwan National Health Insurance Research Database (NHIRD). We also selected a comparison cohort that was randomly frequency-matched by age (each 5-year span), sex and index year from the general population. We analysed the risks of DVT and PE using Cox proportional hazards regression models, including sex, age and comorbidities.

Results From 23.74 million people in the cohort, 29 238 RA patients (77% women, mean age of 52.4 years) and 1 16 952 controls were followed 1 93 753 and 7 92 941 person-years, respectively. The risk of developing DVT and PE was 3.36-fold and 2.07-fold, respectively, in patients with RA compared with patients without RA, after adjusting for age, sex and comorbidities. The multiplicative increased risks of DVT and PE were also significant in patients with RA with any comorbidity.

Conclusions This nationwide prospective cohort study demonstrates that DVT and PE risks significantly increased in patients with RA compared with those of the general population.