Background In rheumatoid arthritis (RA), self assessment of disease activity by patients could be useful in clinical practice. Data in literature regarding the relevance of self-assessment remain limited. We therefore addressed this issue in the Rotation Or Change of biologics (ROC) trial.
Objectives To compare self-assessment of disease activity by patients to assessment of disease activity by physicians in RA.
Methods The ROC trial randomized patients with an insufficient response to a 1st anti-TNF to receive either a second anti-TNF or a non-TNF targeted biologic. At enrollment in the trial, a very brief oral information on self assessment of disease activity, along with a short written reminder, was provided to patients. Within 2 weeks of enrollment and at 6 months, patients received a phone call by a clinical research technician to collect the self-DAS28 (patient-derived DAS28). The clinical research technician was unaware of the arm of randomization and of the result of the DAS28. The concordance between self-DAS28 and DAS-28-ESR assessed by the physician was analyzed using the Bland and Altmann method.
Results At enrollment, self-DAS28 was collected in 97 patients treated with a non TNF-targeted biologic and in 94 patients treated with a second anti-TNF. Mean (SD) self-DAS28 was 4.97 (1.46) and mean DAS28-ESR assessed by the physician was 5.06 (1.10). The systematic difference between self DAS-28 and DAS28 (statistically significant if the confidence interval does not include 0) was -0.11 [-0.29; 0.07]. Thus, self-DAS28 at enrollment sligthly but not significantly underestimated DAS28 assessed by the physician.
At 6 months, self-DAS28 was collected in 91 patients treated with a non TNF-targeted biologic and in 84 patients treated with a second anti-TNF. Mean (SD) self-DAS28 was 3.82 (1.56) and mean DAS28-ESR assessed by the physician was 3.53 (1.40). The systematic difference between self DAS-28 and DAS28 was 0.29 [0.09; 0.46]. Thus, self-DAS28 sligthly but not significantly overestimated DAS28 at 6 months.
Conclusions Self-assessment of disease activity by patients, even without a long period of training, provides a correct appreciation of genuine disease activity in RA. Self-assessment of disease activity could be helpful for patients to have a better perception of disease activity between times of referrals to their rheumatologist, and might therefore contribute to optimize disease control in RA.
Disclosure of Interest None declared