Collating healthcare claims information into a database will enhance understanding of the links between rheumatoid arthritis (RA) treatment and adverse events, scientists say.
Researchers have claimed that the complications commonly seen in those with RA are more often side effects of treatment than related to actual disease.
Assuming that this is the case, disease severity becomes a key determinant of adverse event rate, since more severe disease is more heavily treated.
Taking this into account, Daniel Solomon (Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA) and co-workers reasoned that healthcare claims data, which reflect medication use, accurately reflect adverse event rate in those with RA.
Solomon and team collated claims data from 120 patients with RA to create the claims-based index for RA severity (CIRAS). To determine the accuracy of the CIRAS database, the authors compared it with a previously validated RA severity dataset based on medical records and known as RARBIS (medical records-based index for RA severity).
Statistical tests showed that CIRAS and RARBIS data were moderately well correlated.
Solomon and colleagues say that the CIRAS index can be used for improved adjustment of RA disease severity in claims data studies.
The authors caution that the validity of CIRAS may be compromised because patient data came predominantly from elderly men, but add: "We do not believe that the CIRAS's value will be limited to this study population."
Reporting in the journal Arthritis Research and Therapy, the authors say that they "plan on assessing the validity of CIRAS in other populations and will examine its ability to adjust for confounding and predictive validity for outcomes known to be associated with severe RA, such as future joint surgeries, higher medical care costs, and use of combination disease-modifying anti-rheumatic drugs."
The authors say that they will also examine whether different forms of CIRAS should be used according to different study outcomes.
Once this examination is complete and studies have been performed in more diverse populations, the investigators believe: "CIRAS may be an important methodological tool for researchers studying RA treatment and complications using health care utilization data.