One of the many exciting recent developments in the field of rheumatology was last year's development of new criteria. There's been much discussion of these criteria here on MyRACentral so to learn more, I interviewed Dr. Gillian Hawker, who was part of the working group that created the criteria.
The first thing I learned is that we had all misunderstood what these criteria are about. The media - even medical media - had been describing the new criteria as diagnostic, stating that they would make it easier to identify rheumatoid arthritis in its early stages. Although the identification part of that statement is true, the criteria are not diagnostic. They are classifying criteria, intended for use in clinical trials testing new medications for RA.
The previous classifying criteria used to define RA were created in 1987. According to Dr. Hawker, they "have a significant limitation as they were derived by trying to distinguish patients with established RA from those with a combination of other definite rheumatological diagnoses. They are therefore not helpful in achieving the goal of identifying patients who would benefit from early effective intervention."
The Biologic medications (Enbrel, Humira, Orencia, etc.) are the driving force behind this change. It is because of the revolutionary impact of these types of drugs that the goal of treatment is now "to prevent individuals from reaching the chronic, erosive disease state that exemplifies the 1987 criteria for RA," Dr. Hawker says. This is a significant change from the past treatment goal of merely slowing the progression of RA.
The efficacy of early intervention has to be demonstrated scientifically and it was therefore necessary to "develop new classification criteria for RA to facilitate the study of persons at earlier stages of RA," Dr. Hawker says. The working group consisted of members from The American College of Rheumatology and the European League against Rheumatism. Dr. Hawker says that the goal of the project was to "develop a set of rules to be applied to newly presenting patients with undifferentiated synovitis that would: identify the subset at high risk for persistent inflammation leading to joint damage; be used as a basis for initiating disease modifying therapy; and that would not exclude classification of patients later in the disease course."
The project had three phases. Dr. Hawker explained that in Phase 1, data from a selection of international patients was used to identify "patient factors, e.g., number and distribution of joints affected, serology and duration of symptoms, and their relative weights (i.e. the comparative importance of these factors), that predicted the subsequent disease in a position to start MTX (i.e., methotrexate)" as this would indicate individual doctor's "opinion that the patient what is risk for developing persistent and/or erosive arthritis that we were currently considered to be 'RA'." In the second phase, expert RA clinicians worked to "reach consensus on factors important in determining the probability of developing RA. Decision analytic software was employed to describe the relative weights for each of the factors," Dr. Hawker said. In the last phase of the project, she explained the results of Phases 1 and 2 were used to "develop a scoring system that would be applicable to newly presenting patients with undifferentiated inflammatory arthritis to permit the identification of those with high probability of developing persistent and/or erosive RA." This scoring system was designed to include a differentiation of "probable" and "definite" RA based on the fact that people may "present for the first time at later stages of disease."