The Risk of Venous Thromboembolism in Systemic Inflammatory Disorders: a United Kingdom (UK) Matched Cohort Study

Blood clots occurring in the legs and in the lungs are relatively common; they occur in around 3 in a 1000 people per year. They can cause disability and are also potentially life threatening. When a clot occurs in the legs it is called a deep vein thrombosis or DVT. When they occur in the lungs they are called a pulmonary embolism or PE. The risk for DVT and PE is higher in people with conditions which cause inflammation. The most common of these are inflammatory bowel disease (ulcerative colitis and Crohn's disease), rheumatoid arthritis, and psoriatic arthritis (a condition comprised of psoriasis and joint inflammation). What is not known is how much higher the risk of DVT and PE is in these groups compared with people without inflammatory disease, and what causes the excess risk in these people. This study aims to assess the measure the exact increase in risk for DVT and PE in people with these inflammatory conditions and to identify which risk factors are most strongly associated with the increased risk. These data should help with an understand the causes of blood clot risk in these inflammatory conditions and in identify targets for reducing risk.