Results of a study presented at EULAR 2012, the Annual Congress of the European League Against Rheumatism, suggest that the newly developed RABBIT Risk Score, which calculates the risk of serious infections in patients with rheumatoid arthritis (RA) who are treated with anti-tumour necrosis factor drugs (anti-TNFs) or conventional disease modifying anti-rheumatic drugs (DMARDs) is a valid and effective tool for rheumatologists to predict risk of serious infection.
The German study used data from 2,603 patients enrolled in the RABBIT register at the start of treatment with anti-TNFs (n=1,327) or conventional DMARDs (n=1,276). The likelihood of serious infection based on individual risk profiles was calculated using the RABBIT risk score. The score was developed by the same group of researchers on a different patient sample.
There was good agreement between observed and expected rates of serious infections. In the anti-TNF group, expected number of infections was 31.5 versus actual number observed which was 33. For conventional DMARDs, the expected number of infections was 14.8 versus the actual number observed which was 13.
“The results of our study validate the RABBIT Risk Score as a useful tool to help identify RA patients at high risk of developing infections when treated with anti-TNFs or DMARDs,” said Professor Angela Zink from the German Rheumatism Research Centre in Berlin, Germany. “This tool could help rheumatologists identify at-risk patients and avoid treatment combinations that have a higher risk of infectious complications. This could also help reducing costs associated with treating the infections.”
In patients who had ≥1 risk factor, including chronic lung disease, chronic renal disease, and age above 60 years, the RABBIT Risk Score also successfully predicted infection (10.0 expected vs 9.0 observed in DMARD group, 6.4 expected vs 6 observed in anti-TNF group).