New ACR/EULAR Guideline Expands RA Remission Definition Save

Newly released guidance for defining remission in rheumatoid arthritis (RA) is expected to increase the number of patients achieving it while maintaining its ability to predict good objective outcomes.

The more relaxed criteria from the American College of Rheumatology (ACR) and the European Alliance of Associations for Rheumatology (EULAR) appeared in joint publications in Arthritis & Rheumatology and the Annals of the Rheumatic Diseases.

Using data from four clinical trials comparing biologic RA drugs to methotrexate alone or placebo, the groups found that it was feasible to accept higher scores for patients' global assessments of disease activity -- 2.0 cm on a standard 10-cm rating scale -- as part of the definition of remission, which still maintained good agreement with remission as defined solely by clinician evaluations.

The adjusted definition retained the same correlations with the risk of radiographic progression and functional disability as seen with prior definitions, said the writing committee, led by Paul Studenic, MD, PhD, of the Karolinska Institute in Stockholm, and the Medical University of Vienna in Austria. Omitting the patient assessment altogether "worsened the prediction of good functional outcomes," the panel added.

Rationale for Change

When compared with the prior threshold for remission of a 1 cm global assessment score, the choice of 2.0 cm increased the proportion of patients achieving remission from 14.8% to 20.6% in early RA and from 4.2% to 6.0% in patients with chronic disease.

"With the validation of the threshold of 2 cm for the [patient global assessment], we propose that these revised ACR/EULAR remission criteria be adopted both for future clinical trials and as a target in clinical practice," Studenic and colleagues wrote.

Up to this point, clinical remission in RA was determined in a number of ways. One involved four evaluations: the patient global assessment, swollen joint count (SJC), tender joint count (TJC), and C-reactive protein (CRP) level. Each of these had to come in at values of 1 or less (in centimeters for the patient assessment and mg/dL for CRP).

Another approach relied on the first three of these evaluations, plus the Clinical Disease Activity Index (CDAI) in place of CRP. A third was based solely on a similar scoring system called the Simplified Disease Activity Index (SDAI).

The 1.0-cm threshold for the patient assessment has since appeared problematic, Studenic and colleagues explained, "because some patients do not achieve it despite the absence of tender and swollen joints and an elevated CRP level."

To determine whether a higher threshold could improve the definition, the committee analyzed data from four recent trials in which a substantial number of patients achieved remission by the then-standard criteria. A total of 2,048 patients participated, including 1,101 with early RA (mean duration 0.8 years) and 947 with established disease (mean duration 7.1 years). Aside from testing different thresholds for the patient assessment (1.0, 1.5, 2.0, and 2.5 cm, as well as omitting it entirely), the requirements that CRP, TJC, and SJC not exceed values of 1 were retained.

Using 2.0 cm as the patient assessment threshold maximized the correlation with CDAI- and SDAI-based definitions and kept the correlations with radiographic and functional assessments. Moreover, the authors suggested, by expanding the number of patients seen as achieving remission, the revised definition reduces the likelihood of overtreatment, as there should be no need to add new drugs or increase dosages in such patients. Indeed, their medication regimens might even be scaled back.

Studenic and colleagues cautioned that such evaluations shouldn't dictate treatment approaches by themselves: "All measurements and their interpretations need, in any case, to be complemented by the discussion between the patient and rheumatology clinician to reflect and decide on the appropriate steps in a shared decision."

Source Reference: Studenic P, et al "American College of Rheumatology/EULAR remission criteria for rheumatoid arthritis: 2022 revision" Arthrit Rheumatol 2022; DOI: 10.1002/art.42347.