Rheumatologists and their patients with rheumatoid arthritis (RA) clearly perceive disease status differently. Adding to a vigorous effort to define the discrepancy, new studies reported at the American College of Rheumatology (ACR) meeting last month refined the insights from studies reported earlier this year.
Studies reported in Arthritis Care and Research and in Arthritis and Rheumatism have both pointed to differences in assessing pain as a chief factor in the discrepancy. In the former report, a team headed by University of Arkansas rheumatologists added differences in perception of fatigue to the sources of disagreement; the latter, from a team at the Medical University of Vienna, found discrepancies as to swollen joint count (SJC).
Two further studies presented at the ACR have supplemented this information. A multicenter US-Canada team studied information from the prospective Canadian Early Arthritis Cohort (CATCH) to address whether the degree of discordance changes over time. The analysis involved 48 patients who were biologic-naïve at baseline, at which time they initiated DMARDs and were followed for at least a year.
During that year, the discrepancy between patient and rheumatologist assessments decreased from 35% to 27%. After a year, when the disease is significantly better controlled, however, pain and swollen joint count continue to figure significantly in disagreements between doctors and their patients about disease status. (Abstract #2109)
Using a different Canadian registry that follows RA patients who have begun first-line treatment with infliximab(Drug information on infliximab) or golimumab, a team from McMaster University and the Universities of Montreal and Victoria compared physician and self-assessments of 841 patients to identify four significant factors that accounted for discrepancies. These included pain and swollen joint count, as in other studies, but also morning stiffness and the health quality of life measure HAQ-DI. (Abstract #2108)
These insights may help to develop better tools to assess disease quality, but a third study reported at ACR may have more immediate value, helping to define those for whom standard treatment protocols should be reconsidered. Archana Jain of the University of Alabama at Birmingham and her team hypothesized that comorbidities such as diabetes and congestive heart failure have an important impact on these differences in perception. At the ACR meeting they presented results of their analysis of this question using data from the Veterans Affairs Rheumatoid Arthritis registry, involved 1305 patients (90% of them men) linked to a decision support system. (Abstract #2106)
Comparing physician and patient assessments of disease status, they found no overall association of comorbidities with discordance in assessments. However, the ratio between swollen joint count (SJC) and tender joint count (TJC) was useful as a predictor. An SJC/TJC ratio less than 0.4 appeared to identify patients most likely to switch biologicals, and therefore might help to identify those for whom traditional treat-to-target strategy cutpoints may not be appropriate, they suggest.