The Development and Validation of a Novel Training Infographic for the Physician Global Visual Analog Scale in Psoriatic Arthritis.

Abstract

Objective: Psoriatic arthritis (PsA) is a heterogenous condition with musculoskeletal and skin manifestations. The physician global visual analog scale (VAS) is an important component of many composite scores used in clinical trials and observational studies. Currently, no training material exists to standardize this assessment.

Methods: The Psoriatic Arthritis Validation of Physician Global VAS (PAVLOVAS) project describes the development of a novel training infographic with stakeholder involvement, which was then evaluated in a Latin square design in which 20 patients with PsA were assessed by 10 clinicians. For each group of 10 patients, 5 assessors conducted traditional assessment (consisting of 66/68-joint count, body surface area, Leeds Enthesitis Index, and dactylitis and nail counts) and 5 assessors conducted a standardized, thorough general examination informed by the infographic. Assessors switched assessment type between groups. The 3-item (3VAS) and 4VAS informed by traditional and infographic methods were compared, alongside other composite scores.

Results: There was strong agreement between traditional and infographic physician global VAS (intraclass correlation coefficient [ICC] 0.69, P = 0.01). This improved to very strong agreement when incorporated into the 3VAS (ICC 0.99, P < 0.001) and 4VAS (ICC 0.99, P < 0.001). The duration of assessment was significantly less for the infographic vs traditional groups (6.5 vs 7.8 mins, P < 0.001). There was moderately high agreement between the 3VAS and 4VAS categories of disease activity, with the same categories defined by Psoriatic Arthritis Disease Activity Score (PASDAS) and Disease Activity Index for Psoriatic Arthritis (DAPSA; χ² 17.0, P = 0.049).

Conclusion: Our group developed and validated a novel training infographic that informs a briefer assessment of the physician global VAS than traditional assessments. This tool has potential applications in training and routine clinical practice.