Patient-Defined Remission of Psoriatic Arthritis is Complex

In patients with psoriatic arthritis (PsA), patient-defined “remission” (REM) and low disease activity (LDA) are largely dominated by disease impact, including pain, as well as disease activity, chronicity and age, comorbidities, and symptoms related to other conditions, proving that REM is multifaceted, according to a study published in Oxford.¹

A “treat to target” (T2T) approach defined as achieving minimal disease activity (MDA) while focusing on the concepts of remission and LDA may improve patient outcomes. Since physicians recognize that REM is not ultimately attainable for all patients, low LDA/MDA may be a more reasonable target.

“In a significant number of patients there was discordance between patients’ opinion and the published outcome measure targets. Little is known about the patients’ perception of remission and what influences this opinion,” explained investigators. “The aim of this study was to utilize study data to further investigate the concept of patient defined remission and identify which factors associate with patient-defined remission or LDA.”

Investigators utilized Remission and Flare in PsA (ReFlaP) data to analyze REM. The observational study used patient data across 21 centers and 14 countries. REM was defined as “At this time, is your psoriatic arthritis in remission, if this means: you feel your disease is as good as gone?” The primary outcome was patient-defined REM and secondary was LDA. Variables were identified using a multivariable logistic regression and principal component analysis (PCA).

Investigators studied demographics, comorbidities, disease characteristics, and a PsA-specific data collection framework. Swollen and tender joint counts, tender entheseal points, active psoriasis, a physician global assessment, and both conventional systemic and biologic disease-modifying antirheumatic drugs (DMARDs) were accounted for. Patient reported outcomes (PROs) assessed pain, Health Assessment Questionnaire (HAQ) disability index, patient global assessment of overall disease activity, skin and joints, and PsAID. Doctors scored patients’ symptoms on a scale of 0-10 to determine if they were caused by active inflammatory disease, severe disease, or other diseases not related to PsA.

In total, of the 424 patients with psoriatic arthritis, 94 (22.2%) individuals self-reported REM and 191 (45.0%) noted that they had only had LDA. The mean age of the group was 52 years and 50.2% were male. Eligible patients had rheumatologist-diagnosed PsA for more than 2 years. Investigators discovered that pain, psoriasis, impact of disease, physician opinion, and Groll comorbidity index were able to predict remission. Variance was 74% of 5 components for the male participants and 80% of 6 components for female participants. Regardless of gender, disease impact, including PsAID, pain, and HAQ accounted for 22.2-27.5% of variance. Results were similar for LDA, but the variance was 64-68%, which suggests that the variation between participants could be explained by other factors that were not analyzed in the model.

The study was limited by only studying patients with over 2 years of disease duration, which may hinder generalization to patients with early disease. Other potential limitations were that about half of patients were receiving bDMARDs and the participants had relatively low disease activity in terms of skin disease.

“These data improve our understanding of the focus on remission as perceived by patients in PsA.Understanding the patient perspective of remission is key to improving the definition of efficacy and effectiveness and to establish optimal treatment outcomes. Whilst disease impact may not always relate directly to disease activity, both must be considered when making therapeutic decisions,” concluded investigators. “This understanding can support effective physician-patient communication and shared decision making, particularly when using a T2T approach.”

Reference:

Coates LC, Robinson DE, Orbai AM, et al. What influences patients' opinion of remission and low disease activity in psoriatic arthritis? Principal component analysis of an international study of 424 patients [published online ahead of print, 2021 Mar 5]. Rheumatology (Oxford). 2021;keab220. doi:10.1093/rheumatology/keab220