Long-term remission of rheumatoid arthritis for 24 weeks allowed 58%-73% of patients to regain full physical function, depending on which disease activity index is used, researchers reported online in Arthritis Research & Therapy.
“Physical function continues to improve over time when remission is maintained,” wrote Dr. Helga Radner and her associates at the Medical University of Vienna. Patients with DAS28 (Disease Activity Score using 28-joint counts including C-reactive protein) remission of at least 24 weeks improved by an average of 0.08 on the Health Assessment Questionnaire (HAQ), while those with sustained SDAI (Simplified Disease Activity Index) remissions improved by an average of 0.04, the investigators said.
Dr. Helga Radner
The changes might seem small, but reflected the “very good” functional status of rheumatoid arthritis (RA) patients who achieve long-term remission, they noted, adding that, “on the group level in this population, the relative further improvement was between a quarter and a third of the initial HAQ assessment.”
Remission is a common treatment goal in RA, but maintaining it is the best way to slow or stop further joint damage. To better understand physical function within the context of sustained remission, the investigators analyzed HAQ disability index functional scores for 4,364 patients with active baseline disease who participated in the ASPIRE, ATTRACT, PREMIER, DE019, ERA, TEMPO, and leflunomide trials (Arthritis Res Ther. 2015;17:203).
In all, 14% of patients remained in DAS28 remission (scoring 2.6 or less) for at least 24 consecutive weeks and 5.8% achieved sustained SDAI remission (3.3 or less), Dr. Radner and her associates reported. Lower baseline disease activity, rheumatoid factor levels, and disease duration all predicted sustained remission (P less than .05 for all associations).
Full physical function, defined as a score of zero on the HAQ, occurred in 58% of patients in DAS28 remission for 24 weeks and in 73% of patients in SDAI remission for 24 weeks. Among patients in sustained DAS28 remission, women were significantly more likely than men to regain full physical function (hazard ratio, 1.41; 95% confidence interval, 1.13-1.76), as were patients with early (less than 2 years), compared with longer-term, disease (HR, 1.29; 95% CI, 1.01-1.65). Seropositivity and treatment regimen did not significantly affect the chances of regaining full function.
The researchers may not have captured some disease fluctuations because of the study design, they said. They also did not account for factors such as psychological status and comorbidities, which can affect physical disability.
The Medical University of Vienna funded the study. The investigators declared no competing interests.