A Study of Guselkumab in Participants With Psoriatic Arthritis (PsA) in a Real-World Setting

Inclusion criteria: * Diagnosis of PsA as per CASPAR classification criteria for at least six months with active PsA defined as a tender joint count (TJC) greater than or equal to (\>=) 3/68 and a swollen joint count (SJC) \>= 3/66 at baseline, or C-reactive protein (CRP) \>=0.3 milligrams per deciliter (mg/dL) if TJC and/or SJC are less than (\<) 3 * a) Total synovitis power doppler ultrasound (PDUS) score \>=2 and inflammation related to power doppler (PD) signal \>=2 for at least 1 affected joint of 48 joints at the baseline visit (before first Guselkumab administration), or b) Total synovitis PDUS score \>=2 and inflammation related to PD signal \>=1 for at least 2 affected joints of 48 joints at the baseline visit (before first Guselkumab administration) * Start guselkumab for the indication of PsA as part of standard clinical practice at the time of enrollment into the observational study or within a maximum of two weeks after the initial baseline visit * Participants must be biologic-naïve or previously exposed to only one biologic Disease-Modifying Antirheumatic Drugs (bDMARD) and/or apremilast/deucravacitinib * At least one clinically involved enthesitis site, defined by SPARCC index \>= 1, and one imaging-detected enthesitis site at baseline Exclusion criteria: * Previous exposure to Guselkumab or to more than one bDMARD for any indications * Prior treatment with Janus kinase (JAK) inhibitors * Contraindications to Guselkumab as per the summary of product characteristics (SmPC) * Current enrollment in other investigational study or participation in other investigational study completed from less than 30 days * Current enrollment in an observational study with Guselkumab sponsored or managed by sponsor