Background/Purpose: From previous cross-sectional research we know that minimal disease activity (MDA) is associated with better health-related quality of life (HRQoL) in psoriatic arthritis (PsA). Whether being in MDA early is related to better outcomes is unknown. We aimed to evaluate the impact of time to MDA on HRQoL at one year follow up in patients newly diagnosed with PsA.

Methods: Data collected in the Dutch southwest early PsA cohort (DEPAR) study was used. PsA patients with a new diagnosis of PsA and not yet treated for PsA with disease-modifying antirheumatic drugs are eligible to participate. MDA status was determined every three months in the first year by trained research nurses. Short Form 36 (SF36) Physical Component Scores (SF36-PCS) and Mental Component Scores (SF36-MCS) were used to assess HRQoL.

Results: In July 2017, 296 patients had had their 1-year visit (mean age 51 years, 53% male). Of those, 96 (32%) were in MDA within three months (early MDA), 78 (26%) between 3 and 12 months (late MDA), 98 (33%) were not in MDA at any time during the first year (no MDA) and 24 (8%) patients could not be assigned to either group due to missing data. 43 early MDA patients (46%) had sustained MDA and 46 (60%) of the late MDA patients. Late MDA patients and no MDA patients had significantly higher baseline tender joint counts, enthesitis scores, and VAS scores than early MDA patients. Methotrexate was also prescribed more frequently in no MDA (81%) and late MDA (79%) groups than early MDA (62%). At baseline SF36-PCS scores were significantly lower in the late and no MDA groups, but after one year only the scores of the no MDA group were significantly lower (Figure 1). 

Conclusion: HRQoL of early MDA patients and late MDA patients did not differ significantly at twelve months, but  patients not in MDA in their first year after diagnosis had significantly worse HRQoL than patients that are in MDA. A quarter of patients was in MDA within three months and in total 58% within the first year.

Research support for this analysis was funded by Pfizer. The company had no role in the study design, collection of data, analysis or interpretation of data, nor in the preparation or approval of the abstract and the decision to submit the abstract

Figure 1. SF36-PCS scores in MDA groups over first year follow up

SF36-PCS: Short-Form 36 Physical Component Summary; MDA: Minimal Disease activity; Early MDA: MDA within three months; Late MDA: MDA within three to twelve months; No MDA: no MDA in first year. Data shown as mean with 95% Confidence Intervals.