Patients who experienced delays in initiating treatment of psoriatic arthritis (PsA) of more than 52 weeks were significantly less likely to achieve minimal disease activity (MDA) and Disease Activity in PSoriatic Arthritis (DAPSA) remission over 3 years of follow-up when compared to patients who were diagnosed earlier, Marinus Vis, MD, said in discussing research he and colleagues presented at ACR Convergence.

Dr Vis is principal investigator in the Department of Rheumatology at Erasmus MC in Rotterdam, Netherlands.

The group that experienced more than 52 weeks delay group also scored significantly worse on Health Assessment Questionnaire–Disability Index (HAQ-DI) than the early diagnosis group, he said.

Dr Vis explained that in rheumatoid arthritis (RA), initiating treatment within 12 weeks after symptom onset has been shown to result in higher remission rates, along with less radiographic progression and functional impairment. “In contrast, in psoriatic arthritis (PsA) a diagnostic delay of 1-2 years is still common,” he said. “PsA guidelines state that DMARDs [disease-modifying antirheumatic drugs] should be started early, with a maximum delay of 1 year. However, it is unknown whether a shorter delay of 12 weeks yields better clinical outcomes. We aimed to investigate what the window of opportunity is in PsA.”

To investigate this issue, Dr Vis and colleagues included 855 patients who participated in the Dutch southwest Early PsA cohort (DEPAR). These patients were newly diagnosed with PsA and naïve to DMARDs.

“First, we calculated total delay, and then split this into patient and general practitioner (GP) delays to assess where potential gains could be made,” he explained. Then the patients were categorized into 3 groups based upon total delay of < 12 weeks delay (early diagnosis); 12-52 weeks delay (late diagnosis); and more than > 52 weeks delay.

The median total delay between presentation of symptoms and start of therapy was 42.0 weeks, Dr Vis stated. Delays by the patient and the general practitioner were 4.4 and 18.0 weeks, respectively. Patients with more than 52 weeks delay were more often female, had fewer swollen joints, and had lower C-reactive protein and erythrocyte sedimentation rates. These patients also more often had enthesitis, he said.

In contrast, Dr Vis noted, “no baseline differences were found between early and late diagnosis groups, respectively < 12 weeks and 12-52 weeks.” The investigators also found no significant difference in radiographic progression between groups.

Patients who experienced more than 52 weeks’ delay were “significantly less likely to achieve MDA and DAPSA remission over 3 years of follow-up compared to both the early and late diagnosis groups,” he said. “The > 52 weeks delay group also scored significantly worse on HAQ-DI than the early diagnosis group.”

Vis M. 1641: The window of opportunity in psoriatic arthritis: similar to rheumatoid arthritis? Presented at: American College of Rheumatology Convergence. November 13, 2023. San Diego, California.