The perception of improved disease activity by patients with rheumatoid arthritis (RA) differs considerably depending on the disease activity level at which they start, study findings indicate.
“Recently, the perspectives of patients have become an increasingly relevant constituent of RA outcomes assessment,” note Daniel Aletha (Medical University of Vienna, Austria) and colleagues.
To assess how a decrease in disease activity, as measured by the Disease Activity Score based on the assessment of 28 joints (DAS28), the Simplified Disease Activity Index (SDAI), and the Clinical Disease Activity Index (CDAI), relates to patient perception of improvement, Aletha and team followed 1050 patients who had recently begun treatment for RA.
Three months after initiation of therapy, patients indicated whether their condition had improved, had considerably improved, was unchanged, had worsened, or had considerably worsened.
The researchers then used receiver operating characteristic curve analysis to determine the minimum clinically important improvements (MCII) for the three composite indices. They also analyzed the effects of different levels of baseline disease activity on the MCII.
On average, patients started with high disease activity and improved significantly during treatment according to the American College of Rheumatology improvement criteria.
Twenty-three per cent of patients reported worsening or no change in disease activity, 45% reported that they had improved, and 32% reported that they had considerably improved.
The overall mean thresholds for MCII after 3 months for the DAS28, SDAI, and CDAI were 1.20, 10.95, and 10.76, respectively, meaning that, for example, the patient required a change in the DAS28 of at least 1.20 to feel improved.
The mean thresholds for a major response were 1.82 for DAS28, 15.82 for SDAI, and 15.00 for CDAI.
Aletha et al observe that there was an almost linear association between baseline disease activity and MSCII. As disease activity increased, much higher changes in disease activity were needed to achieve MCII according to patient judgment.
Writing in the journal Arthritis Care and Research, the team concludes that evaluation of patient reported improvement will “add an important layer to the interpretation of outcomes in clinical trials, observational studies, and clinical practice.”
Just a side question, has anyone ever asked their RD for their DAS?
Prior to remission I had DAS measured. Not sure how accurate because of damage to joints. DAS was again attempted when I started remission but due to damaged joints was difficult to accurately proceed. My RD ordered MRIs of my worst joints and when the MRI showed no synovial fluid accumulation and labs were negative then he felt that I had achieved clinical remission. LindyI am always frustrated with the questionairre I get at the rheumy's office -- it asks if I was unable to do buttons, lift a mug, or get out of a car, etc. I can do these things, but the pain level is the problem, not whether I can do them or not. I feel like my answers make me seem less affected than I really am... My rheumy hasn't done any xrays/mri's etc for several years, so I really don't know how I'm doing...They've never shared any scores with me.