Evaluating the psychosocial and clinical impact of diagnostic delay in psoriatic arthritis: insights from a monocentric cohort.

Objectives: Our aim was to investigate the association between diagnostic delay and the clinical and psychosocial features in patients with psoriatic arthritis (PsA), with particular focus on the mental health, wellbeing, and pain-related mechanisms. Methods: A monocentric cross-sectional study was conducted including consecutive patients with PsA classified according to the Classification Criteria for Psoriatic Arthritis. Diagnostic delay was defined as the time between symptom onset and diagnosis, and patients were stratified according to delays ≥1 year and ≥2 years. Clinical assessment included demographic and clinical parameters, such as the Psoriasis Area and Severity Index (PASI), Leeds Enthesitis Index (LEI), Disease Activity in Psoriatic Arthritis (DAPSA), and treatment history. Psychosocial evaluation included evaluation of pain, fatigue, and sleep quality using the Numeric Rating Scale (NRS) from the corresponding Psoriatic Arthritis Impact of Disease (PsAID) domains, Hospital Anxiety and Depression Scale (HADS), the Mental Health Continuum-Short Form (MHC-SF), the PainDETECT questionnaire (PDQ), the Central Sensitization Inventory (CSI), and the Brief Pain Inventory (BPI). Patients were stratified according to the presence of at least 1 year or at least 2 years of diagnostic delay. Univariable and multivariable analyses were performed to compare the demographic and clinical variables across different groups and to identify factors associated with the diagnostic delay. Results: A total of 112 patients were enrolled, with 38.4% experiencing a diagnostic delay ≥1 year and 25.8% a delay ≥2 years. Both groups showed higher BMI, longer disease duration, and higher NRS pain compared with patients with less than 1 year and less than 2 years of delay. No significant differences were observed in disease activity, fatigue, sleep, PDQ, CSI, and BPI. Lower social wellbeing assessed through the MHC Social Well-Being (MHS-SWB) subscale was observed in patients with >2 years of delay. Two logistic regression models selecting diagnostic delay >2 years as the dependent variable and MHC-SWB first, then NRS pain together with BMI, disease duration, and DAPSA as covariates, confirmed the independent association of both NRS pain (OR = 1.3, 95%CI = 1-1.6) and MHC-SWB (OR = 0.9, 95%CI = 0.8-0.9) with diagnostic delay. Conclusion: Diagnostic delay in our PsA cohort is independently associated with higher patient pain perception and reduced social wellbeing, suggesting an association with selected patient-reported outcomes beyond traditional clinical outcomes. However, the lack of association with other measures, such as central sensitization, depression, and anxiety, supports a multifactorial and incomplete interpretation, highlighting the need for larger, longitudinal studies to clarify the relationship between diagnostic delay and psychosocial outcomes.