Study adds new insight into risk of thromboembolism in patients with RA

Earlier studies have shown that people with rheumatoid arthritis (RA) are more likely to develop blood clots in the legs or lungs - venous thromboembolism - especially in conjunction with hospitalisation. It has therefore been suggested that people with RA be given routine anticoagulants when admitted to hospital. Researchers at Karolinska Institutet have now shown in a large-scale registry study that although this patient group is indeed more likely to develop thromboembolisms, the risk is different to what was previously feared. The study, which is published in the scientific journal JAMA, renews medical science's understanding of how the risk of thromboembolism - or the lodging of a blood clot in a blood vessel - changes with time for RA patients. "Some previous studies have only included people who are in hospital for RA," says Marie Holmqvist, researcher at the Department of Medicine in Solna. "But today it's not so common amongst these patients, which means that studies are done on people who are more than averagely sick. It's also hard to make out if the increased risk of venous thromboembolism is attributable to the RA itself or to a generally higher risk connected with being in hospital." For this present study, the researchers therefore examined, on the one hand, the risk of thromboembolism amongst patients with RA who had not been identified on the basis of hospitalisation, and the risk of thromboembolism amongst hospital patients on the other.