Correlation of patient-reported routine assessment of patient index data with clinical measures of disease activity in psoriatic arthritis

Abstract

Aim: A treat-to-target strategy is recommended for management of psoriatic arthritis (PsA), although there is lack of agreement regarding the best measure of disease activity to target. Physician assessments included in traditional indices can be complex and time consuming to complete and cannot be readily conducted by telehealth. This study compares the routine assessment of patient index data 3 (RAPID3), an efficient tool comprising patient self-assessment, with traditional clinician-led composite measures in the PsA clinic setting.

Methods: Data were collected prospectively from July 2016 to March 2020 in 2 dedicated PsA clinics in Sydney, Australia. A receiver operating characteristic (ROC) curve was created for comparison of RAPID3 score with composite scores minimal disease activity (MDA), very low disease activity (VLDA) and disease activity in psoriatic arthritis (DAPSA) in low disease activity or remission.

Results: Ninety-three patients had simultaneous collection of RAPID3 and MDA measures. Mean (SD) age was 49.9 (13.5) years, 50.5% were male and 23 (24.7%) had erosive disease at baseline. RAPID3 scores ≤3.2 and ≤2.7 (range 0-30) had high sensitivity and specificity for VLDA and DAPSA remission respectively, with ROC curve area under the curve (95% CI) of 0.94 (0.91-0.97) and 0.96 (0.93-0.99).

Conclusion: RAPID3 has good agreement with physician-led composite scores of MDA, VLDA and DAPSA, and provides a viable alternative to composite scores. This is particularly helpful in settings that do not allow for clinical examination, for example telehealth.

Keywords: arthritis; arthritis, psoriatic; patient-reported outcome measures; spondyloarthritis; treatment outcome.

FIGURE 1

Receiver operator characteristic (ROC) curve for minimal disease activity (MDA)/very low disease activity (VLDA) and routine assessment of patient index (RAPID3). The ROC curves show the ability of RAPID3 to identify patients who meet MDA activity criteria (Figure 1A) and those who meet VLDA criteria (Figure 1B). The red line is a reference line indicating area under the curve (AUC) of 0.5, corresponding to no discriminatory ability of the test. The AUC (95% CI) for RAPID3 to discriminate patients who meet MDA compared to patients who do not meet criteria was 0.91 (0.87‐0.95). The AUC (95% CI) for RAPID3 to discriminate patients who meet VLDA criteria was 0.94 (0.91‐0.97)

FIGURE 2

Receiver operator characteristic (ROC) curve for disease activity in psoriatic arthritis in low disease activity and remission (DAPSA‐LDA)/disease activity in psoriatic arthritis in remission (DAPSA‐REM) and routine assessment of patient index (RAPID3). The ROC curves show the ability of RAPID3 to identify patients who meet DAPSA‐LDA (Figure 2A) and DAPSA‐REM criteria (Figure 2B). The red line is a reference line indicating area under the curve (AUC) of 0.5, corresponding to no discriminatory ability of the test. The AUC (95% CI) for RAPID3 to discriminate patients who meet DAPSA‐LDA compared to patients who do not meet criteria was 0.90 (0.87‐0.94). The AUC (95% CI) for RAPID3 to discriminate patients who meet DAPSA‐REM criteria was 0.96 (0.93‐0.99)

FIGURE 3

Venn diagram for the relationship of routine assessment of patient index (RAPID3) with minimal disease activity (MDA) and disease activity in psoriatic arthritis with low disease activity (DAPSA‐LDA). The Venn diagram in Figure 3A demonstrates the relationship between the number of patient visits in which patients met MDA criteria (light gray; Figure 3A) and the number of patient visits in which patients reported a RAPID3 score ≤6 (dark gray; Figure 3A). In 67 patient visits, patients were in MDA and scored RAPID3 ≤6. In 14 patient visits, patients were in MDA but scored RAPID3 >6. Figure 3B demonstrated the relationship between patients who meet DAPSA‐LDA criteria (light gray; Figure 3B) and the number of patients who report a RAPID3 score ≤10 (dark gray; Figure 3B). In 92 patient visits, patients were in DAPSA‐LDA and scored RAPID3≤10. In 18 patient visits, patients were in DAPSA‐LDA but scored RAPID3 >10