Rheumatoid arthritis patients were less likely than their physicians to score themselves as being in clinical remission on a widely used clinical composite index, based on a prospective, cross-sectional study.
Meanwhile, ultrasound assessments also showed variable correlation with both patient and physician assessments of tender and swollen joints in the study of 69 patients with RA who were judged to be in clinical remission by their rheumatologist, according to lead investigator Dr. Iustina Janta of the Hospital General Universitario Gregorio Marañón, Madrid, and her colleagues.
"Accurate assessment of RA activity in a nonactive state is of the utmost importance because therapeutic decisions should target sustained remission or, at a minimum, the lowest possible disease activity to improve RA outcomes," Dr. Janta and her coauthors wrote (Rheumatology 2013 Sept. 17 [doi:10.1093/rheumatology/ket297]).
Dr. Iustina Janta
The mean age of the cohort was 60 years, and most of the patients were women (77%). The patients’ mean disease duration was nearly 12 years, and overall, 70% were in treatment with synthetic disease-modifying antirheumatic drugs. Another 16% took biologics, and the remainder used both classes of drugs.
To assess concordance between patient and physician assessments of disease activity, patients first indicated to the investigators which joints on a mannequin corresponded to their own tender or swollen joints. They also ranked their global health assessment on a visual analogue scale from 0 to 10.
A physician blinded to each patient’s own assessment then recorded an assessment of each patient’s tender joint count and swollen joint count, as well as the physician’s perception of the patient’s global assessment of disease activity.
Dr. Janta and her associates found that the mean scores calculated on the Disease Activity Score 28 (DAS28) were significantly higher according to patients, at 3.34, compared with the physician tally, at 2.55 (P less than .0005).
Indeed, even though the attending rheumatologist had judged all 69 patients to be in clinical remission, DAS28 scores calculated from the patients’ assessments indicated that only 18 patients (26%) fit this bill. But according to the physician assessment, that number was 36 patients (52%) – another significant difference (P less than .0005).
Next, the researchers assessed concordance between doctors and patients on the simplified disease activity index (SDAI). Here, there was better agreement: The mean score assessment among patients was 12.33, compared with a physician mean assessment of 10.55 (P = .246). That translated to a statistically similar SDAI-based remission rate of 15% according to patients vs. 12% according to physicians (P = .172).
Finally, ultrasound examinations with B mode and power Doppler showed no significant correlations with patient- and physician-derived clinical assessments. The mean number of tender joints was 4.34 based on patient assessment, 3.12 by physician examination, and 4.09 based on B-mode ultrasound.
On the other hand, swollen joint counts (SJCs) were significantly lower in both patient (2.00) and physician (1.42) estimation, compared with B-mode ultrasound (4.09) (P less than .0005 for ultrasound vs. patient mean SJC; P = .033 for ultrasound vs. physician SJC).
The ultrasound results on power Doppler were reversed in comparison with B-mode assessment. Tender joint counts were much higher when estimated by patients (4.34) and physicians (3.12), compared with Doppler ultrasound (1.1, P less than .0005 for both).
But mean swollen joint counts on power Doppler ultrasound (1.1) correlated well with patient- and physician-assessed counts (2 and 1.42, respectively).
Dr. Janta and her associates wrote that in the future, given the current trend in patient involvement in disease activity assessments throughout the field, "longitudinal studies should investigate the predictive capability of patient self-assessment of RA activity in relation to relevant disease outcomes, which will address the real value of the discrepancies between patient-assessed and physician-assessed RA activity."
They also noted that "studies on the optimal weight of power Doppler findings in global RA activity assessment are needed."
The authors stated that they had no relevant financial conflicts. They did not report any outside funding for this study.