Impact of concomitant fibromyalgia on patient-reported outcomes and inflammatory markers in psoriatic arthritis: a multinational cross-sectional study.

Fibromyalgia (FM) is frequently observed in patients with psoriatic arthritis (PsA) and can contribute to reduced quality of life (QoL) and potentially unnecessary treatment escalation. Cultural factors may influence the presentation and impact of FM. To determine the prevalence of FM in patients with PsA using the Fibromyalgia Rapid Screening Tool (FiRST), identify associated clinical factors, and assess agreement between FiRST results and physician-reported FM based on clinical opinion. post-hoc, cross-sectional study of the multicounty TACTIC dataset across 13 Arab countries. FM was defined by a FiRST ≥ 5. We compared Disease activity (DAPSA), Physician Global Assessment (PhGA), and validated patient-reported outcomes (PROs), and fitted a multivariable logistic model to identify predictors. Agreement between FiRST and physician-reported FM was assessed using the Intraclass Correlation Coefficient (ICC), diagnostic discrimination of FiRST against physician reported FM was evaluated by ROC/AUC. Among 536 PsA patients, 19.0% screened positive for FM (FiRST ≥ 5). In multivariable analysis, higher BMI, dyslipidemia, non-oligoarticular pattern, lower ESR, higher DAPSA, and higher PHQ-4 were independently associated with FM. Agreement between FiRST and physician-reported FM status was moderate (ICC 0.59; 95% CI 0.51–0.66), and FiRST discrimination for physician diagnosis was excellent (AUC = 0.833, 95% CI 0.793–0.873). Approximately 1 in 5 patients with PsA in Arab countries screened positive for FM. FM was associated with higher disease activity and PRO burden despite lower ESR. Findings support routine FM screening in PsA, particularly when PROs are high but inflammatory markers are low, to ensure assessment and holistic management.