Psoriatic arthritis (PsA) is a chronic inflammatory disease with heterogeneous musculoskeletal and dermatologic manifestations, leading to significant functional impairment and reduced quality of life. Although targeted therapies such as Janus kinase inhibitors and interleukin-17 inhibitors have demonstrated efficacy in randomized controlled trials, real-world comparative evidence between these treatment strategies remains limited.

This observational cohort study aims to compare the real-world effectiveness and safety of upadacitinib and interleukin-17 inhibitors in patients with PsA over a 24-week follow-up period. By evaluating clinical outcomes under routine clinical practice conditions, this study seeks to provide evidence to support individualized treatment selection in PsA management.

This is a real-world, observational cohort study conducted at Peking University First Hospital. Adult patients diagnosed with psoriatic arthritis will be enrolled and followed for 24 weeks in routine clinical practice.

Participants will be categorized into two cohorts based on treatment exposure at baseline: patients receiving upadacitinib and patients receiving interleukin-17 inhibitors. Treatment decisions are made by treating physicians according to standard clinical practice and are not influenced by the study protocol.

Clinical assessments will be performed at baseline and during routine follow-up visits within the 24-week observation period. Effectiveness outcomes will be evaluated across musculoskeletal and dermatologic domains, and safety outcomes will be monitored throughout follow-up. This study does not involve experimental interventions.

Inclusion Criteria:

• Age ≥ 18 years
• Diagnosis of psoriatic arthritis according to established classification criteria
• Treatment with upadacitinib or an interleukin-17 inhibitor at baseline
• Availability of baseline and follow-up clinical data over 24 weeks

Exclusion Criteria:

• Diagnosis of other inflammatory arthritides
• History of malignancy or severe uncontrolled infection
• Incomplete clinical data preventing outcome assessment

Diagnosis of psoriatic arthritis according to established classification criteria