Validation of the Physician's Global Assessment of Fingernail Psoriasis by Rheumatologists Treating Psoriatic Arthritis.

Objectives: This study aimed to assess the content validity and reliability of the Physician's Global Assessment of Fingernail Psoriasis (PGA-F) by rheumatologists treating patients with psoriatic arthritis.

Methods: There were 3 stages of analyses with 3 clinician cohort groups. Stage 1 (concept confirmation) included rheumatologist qualitative data (cohort 1) to establish content validity, acceptability, utility, and feasibility of the PGA-F in assessing nail severity.