BRIGHTON, ENGLAND – Use of the 2010 classification criteria for rheumatoid arthritis that were developed jointly by the American College of Rheumatology and the European League Against Rheumatism could result in overdiagnosis and subsequent overtreatment of early disease.
Although the 2010 ACR/EULAR criteria for RA classification allow for the more rapid identification of patients early in the course of the disease, their widespread use could also mean that some people with an essentially self-limiting illness could be given unnecessary – and perhaps too aggressive – treatment.
Study findings that were presented April 12 at the annual meeting of the British Society for Rheumatology found that more than 30% of 265 patients with early synovitis were identified as having RA via the 2010 ACR/EULAR criteria only (Arthritis Rheum. 2010;62:2569-81). In comparison, around half the number of patients (17.7%) were identified using the 1987 ACR criteria (Arthritis Rheum. 1988;31:315-24) alone.
"When we look at the early, and often undifferentiated phase, of arthritis, this poses a potential dilemma to clinicians," study author Dr. Zaeem Cader of the Rheumatology Research Group at the University of Birmingham (England) commented.
"The disease of many patients will resolve without ever requiring treatment," he observed, "whilst others progress to a persistent arthritis. And within this category, some patients may convert to an established rheumatoid phenotype, with others developing a non-RA, but persistent, arthropathy."
It is within the latter group that the 1987 ACR classification criteria were originally developed, Dr. Cader explained; those criteria aimed to help differentiate RA from other rheumatologic joint conditions of several years’ duration.
In recent years, however, it has become clear that the earlier RA is treated, the better the outcome in terms of radiologic progression, which can be halted or prevented with the use of DMARDs (disease-modifying antirheumatic drugs) very early on in the course of the disease.
With this in mind, Dr. Cader and associates looked at whether the updated 2010 ACR/EULAR criteria could better identify patients within the first 3 months of symptom onset in their early RA cohort.
In all, 265 patients with clinically apparent synovial swelling in one or more joint were studied; they had a mean age of 49 years and median symptom duration of 42 days. The percentage of patients meeting 2010 criteria only at baseline was 17.4%, whereas 2.3% met ACR criteria only, 15.5% met both, 42.2% neither, and 22.6% had a clear, alternative diagnosis to RA.
After 18 months of treatment, however, reassessment of patients showed that only 6% and 7%, respectively, still met either the 2010 or 1987 criteria, with 28.8% fulfilling both sets of criteria, 29.9% fulfilling neither, and 27.9% not being diagnosed with RA.
Application of the new criteria vs. the old at baseline also detected significantly more patients who would later require methotrexate or another DMARD, but the use of the new criteria also detected significantly more patients whose disease spontaneously resolved (in both, P less than .01).
"Classification is not the same as diagnosis," Dr. Cader conceded. "However, two core goals of the new criteria were to identify patients who were at risk of progressing to persistent disease, and [to identify] patients who will require treatment with drugs such as methotrexate."
Although the authors of the 2010 criteria resisted a direct comparison, or even basing the new criteria on the old, Dr. Cader argued that this was an important comparison to make. Indeed, if the 2010 criteria are more widely used, it’s important to know if they do indeed meet the goal of more rapidly identifying patients. In addition, it might be hard to translate findings from epidemiologic and clinical research based on these old criteria.
"The early identification of patients at risk of developing RA will allow for the early institution of treatment and improved clinical outcomes," the senior author of the study Dr. Karim Raza said separately in a press statement.
Dr. Raza, a senior lecturer and honorary consultant rheumatologist at the University of Birmingham, cautioned however, that the use of the updated RA criteria could lead to the overdiagnosis and subsequent overtreatment of patients.
"The new 2010 ACR/EULAR criteria represent an important step in that direction. However, detailed testing of these criteria in other cohorts is needed to fully assess to what extent ‘overtreatment’ would be a problem if these were widely applied."
Dr. Cader stated that he had no conflicts of interest. Dr. Raza and other coauthors disclosed receiving research grants from Cellzome, UCB, and Wyeth.