{
  "abstract": "Objectives To determine the frequency and baseline characteristic differences of complex-to-manage (C2M), difficult-to-manage (D2M) and treatment-refractory (TR) psoriatic arthritis (PsA) in a real-world longitudinal cohort, using the recently proposed 2025 Group for Research and Assessment of Psoriasis and Psoriatic Arthritis (GRAPPA) and the European Alliance of Associations for Rheumatology (EULAR) definitions.Methods We analysed data from newly diagnosed, disease-modifying antirheumatic drug-naïve patients with PsA enrolled in the Dutch Southwest Early Psoriatic Arthritis cohort between 2013 and 2023. Patients were classified using the 2025 GRAPPA (C2M, TR) and EULAR (D2M, TR) PsA definitions. Frequencies were calculated for each definition. Time-to-event analyses using Kaplan-Meier methods assessed the timing of definition fulfilment and individual components. Longitudinal differences in patient-reported outcomes (PROs) were assessed using linear mixed-effects models.Results Among 885 newly diagnosed patients with PsA, 20% (179/885) fulfilled the GRAPPA-C2M definition, 4.2% (37/885) fulfilled the EULAR-D2M definition, 3.8% (34/885) met the EULAR-TR and 1.2% (11/885) fulfilled the GRAPPA-TR criteria definition during follow-up. Female sex, higher body mass index (BMI), longer symptom duration, presence of enthesitis and greater skin involvement differed with meeting definitions at baseline. Patients classified as GRAPPA-C2M, GRAPPA-TR, EULAR-D2M and EULAR-TR consistently reported worse long-term PROs (Health Assessment Questionnaire-Disability Index scores in C2M (β=0.17, 95% CI 0.10 to 0.24), GRAPPA-TR (β=0.37, 95% CI 0.22 to 0.51), EULAR-D2M (β=0.36, 95% CI 0.20 to 0.48) and EULAR-TR (β=0.40, 95% CI 0.25 to 0.55)).Conclusions Approximately 20% of patients with early PsA fulfilled the GRAPPA-C2M criteria, representing the earliest and broadest subgroup, while 4% met EULAR-D2M/EULAR-TR and 1.2% GRAPPA-TR definitions. These latter subgroups were more likely to be female, had higher BMI, greater skin involvement and enthesitis and experienced persistently worse PROs, underscoring the need for tailored management strategies.",
  "authors": [
    {
      "affiliations": [
        "Department of Rheumatology, Erasmus MC, Rotterdam, The Netherlands"
      ],
      "name": "Gonul Hazal Koc"
    },
    {
      "affiliations": [
        "Department of Rheumatology and Clinical Immunology, Maasstad Hospital, Rotterdam, The Netherlands"
      ],
      "name": "Marc R Kok"
    },
    {
      "affiliations": [
        "Department of Rheumatology, Erasmus MC, Rotterdam, The Netherlands"
      ],
      "name": "Selinde V J Snoeck Henkemans"
    },
    {
      "affiliations": [
        "Department of Rheumatology, Erasmus MC, Rotterdam, The Netherlands"
      ],
      "name": "Jolanda J Luime"
    },
    {
      "affiliations": [
        "Department of Rheumatology, Albert Schweitzer Ziekenhuis, Dordrecht, The Netherlands"
      ],
      "name": "Ilja Tchetverikov"
    },
    {
      "affiliations": [
        "Department of Rheumatology, Franciscus Gasthuis & Vlietland, Rotterdam, The Netherlands"
      ],
      "name": "Lindy A Korswagen"
    },
    {
      "affiliations": [
        "Department of Rheumatology, Amphia Hospital, Breda, The Netherlands"
      ],
      "name": "Natasja H A M Denissen"
    },
    {
      "affiliations": [
        "Department of Rheumatology, Haga Hospital, The Hague, The Netherlands"
      ],
      "name": "Yvonne P M Goekoop-Ruiterman"
    },
    {
      "affiliations": [
        "Department of Rheumatology, Reumazorg Zuid West Nederland, Goes, The Netherlands"
      ],
      "name": "Paul Baudoin"
    },
    {
      "affiliations": [
        "Reumazorg Zuid West Nederland, Reinier de Graaf Gasthuis, Delft, The Netherlands"
      ],
      "name": "Petra Kok"
    },
    {
      "affiliations": [
        "Reumazorg Zuid West Nederland, Medical Centre Leeuwarden, Leeuwarden, The Netherlands"
      ],
      "name": "Reinhard Bos"
    },
    {
      "affiliations": [
        "Department of Rheumatology, Erasmus MC, Rotterdam, The Netherlands"
      ],
      "name": "Radboud J E M Dolhain"
    },
    {
      "affiliations": [
        "Department of Gastroenterology, Infectiology and Rheumatology, Charite Universitatsmedizin Berlin, Berlin, Germany"
      ],
      "name": "Fabian Proft"
    },
    {
      "affiliations": [
        "Department of Rheumatology, Erasmus MC, Rotterdam, The Netherlands"
      ],
      "name": "Marijn Vis"
    },
    {
      "affiliations": [],
      "name": "CICERO"
    }
  ],
  "title": "Frequency of complex-to-manage, difficult-to-manage and treatment-refractory psoriatic arthritis: applying the 2025 GRAPPA and EULAR definitions in a real-world longitudinal PsA cohort",
  "uid": "c8a6d565-c4fb-5093-8074-bc738586b983"
}