Background/Purpose: T2T guidelines for psoriatic arthritis (PsA) propose using DAPSA or MDA to define the therapeutic target, but with differences in preference among experts. Objective: To determine the performance of MDA and DAPSA in the evaluation of disease activity in PsA patients.

Methods: Patients with PsA according to CASPAR criteria ≥ 18 years old were included. Sociodemographic data, comorbidities and current treatment were registered. Morning stiffness, pain, patient´s (PtGA) and physician´s global assessment (PGA) were consigned. Joint count (66/68), dactylitis, enthesitis (MASES), Psoriasis (PASI) and axial mobility (BASMI) were evaluated. ESR (mm/h) and CRP (mg/dl) were determined. Self-questionnaires were performed to assess: quality of life (PsAQoL, ASQoL), functional capacity (HAQ, BASFI) and disease activity (BASDAI). The composite indices were calculated: DAPSA, DAPSA-ESR, DAS28, CDAI, SDAI, CPDAI, and minimal disease activity (MDA). Statistical analysis: Descriptive statistics. Student’s T test and ANOVA. Chi² test, Fisher exact test.

Results: 129 patients were included, 52.7% were male, with a median age of 56 years (IQR: 44-65). The median disease duration was 12 years (IQR: 7-18) and the median psoriasis duration was 21 years (IQR: 14-30). 58.9% had peripheral joint involvement, 2.3% axial involvement and 38.8% presented mixed involvement. The median of DAPSA was 13.3 (IQR: 7.4-21.7) and according to its cut-off values 3.9% of the patients were in remission, 26% in low disease activity, 55.8% in moderate and 14.3% in high disease activity. 31 patients (24%) met the MDA criteria. The cohort was dichotomized according to DAPSA: in those in remission and low activity, T2T group (10 and 56 respectively, total 66 patients) and in those with moderate and high disease activity, no T2T group (43 and 20 respectively, total 63 patients). We observed that 100% of patients who met MDA criteria were in remission and low disease activity categories by DAPSA. On the other hand, among patients who did not meet the MDA criteria, 46% had moderate and high disease activity according to DAPSA, while 35% (34 patients) were in low disease activity. The main reasons because of these patiens did not met MDA criteria, were: pain≥15mm (100%), PtGA ≥20mm (79%) HAQ-A ≥0.5 (62%) and PASI ≥1 (56%). Of the 34 MDA/DAPSA discordant patients, a therapeutic change was made only in 11 of them, and they were: change of pharmacological treatment (55%), joint infiltration (27%) and consultation with the dermatologist due to skin disease activity (18%). The only variable associated with a therapeutic change was higher joint tender count in the univariate analysis, however, it did not remain significant in multivariate analysis, after adjusting for confounding variables.

Conclusion: The agreement of MDA and DAPSA was good in our cohort of PsA patients. In 60% of the discordant patients, treatment was not modified. It seems that both composite indexes are effective for monitoring T2T in daily clinical practice.

ACR Meeting Abstracts - https://acrabstracts.org/abstract/defining-the-therapeutic-target-in-psoriatic-arthritis-mda-versus-dapsa/