Back to Journals » Psoriasis: Targets and Therapy » Volume 8

The Physician Global Assessment and Body Surface Area composite tool is a simple alternative to the Psoriasis Area and Severity Index for assessment of psoriasis: post hoc analysis from PRISTINE and PRESTA

Authors Walsh JA, Jones H, Mallbris L, Callis Duffin K, Krueger GG, Clegg DO, Szumski A

Received 26 March 2018

Accepted for publication 7 May 2018

Published 8 October 2018 Volume 2018:8 Pages 65—74


Checked for plagiarism Yes

Review by Single anonymous peer review

Peer reviewer comments 2

Editor who approved publication: Prof. Dr. Uwe Wollina

Jessica A Walsh,1 Heather Jones,2 Lotus Mallbris,2 Kristina Callis Duffin,3 Gerald G Krueger,3 Daniel O Clegg,1 Annette Szumski4

1Division of Rheumatology, Department of Internal Medicine, University of Utah School of Medicine, Salt Lake City, UT, USA; 2Inflammation and Immunology,Global Medical Affairs, Pfizer, Collegeville, PA, USA; 3Department of Dermatology, University of Utah School of Medicine, Salt Lake City, UT, USA; 4Pfizer Business Unit (PBU) Syneos Health, Princeton, NJ, United States

Background: The product of Physician Global Assessment and Body Surface Area (PGA × BSA) is a new outcome measure for psoriasis severity and response to therapy. The objective of this study was to evaluate PGA × BSA as an alternative to Psoriasis Area and Severity Index (PASI) for psoriasis assessments.
Methods: The relationship between PASI and PGA × BSA was assessed in a post hoc analysis of pooled data from the PRISTINE (NCT00663052) and PRESTA (NCT00245960) trials in patients with moderate-to-severe psoriasis who received etanercept 50 mg/week. Data were analyzed using Spearman and intra-class correlation coefficients, effect sizes, scatterplots, Bland–Altman plots, and Kappa statistics.
Results: Spearman correlations at baseline, week 12, and week 24 were strong for PGA × BSA versus PASI (r=0.78, 0.87, and 0.90, respectively; all P<0.0001) as were intra-class correlations (0.76 [95% confidence interval 0.73–0.80], 0.80 [0.76–0.83], and 0.85 [0.82–0.87], respectively). The effect size was −1.53 for PASI and −0.94 for PGA × BSA (baseline to week 24). Scatterplots and Bland–Altman plots detected a trend across the range of measurement. Kappa statistics (at 12 and 24 weeks) between PASI50/75/90 and 50/75/90% improvement in PGA × BSA showed good agreement (0.58–0.69 at week 12 and 0.63–0.67, respectively; all P<0.0001). At baseline, the Spearman correlation coefficients were 0.96, 0.51, 0.19, and 0.17 for PGA × BSA versus BSA, PGA, Patient Global Assessment, and Dermatology Life Quality Index, respectively (all P<0.001).
Conclusion: PGA × BSA has advantages over PASI for measuring moderate-to-severe psoriasis; it is intuitive, sensitive, and easy to use.

Keywords: etanercept, PASI, PGA × BSA, psoriasis, correlation, agreement, responsiveness

Creative Commons License This work is published and licensed by Dove Medical Press Limited. The full terms of this license are available at and incorporate the Creative Commons Attribution - Non Commercial (unported, v3.0) License. By accessing the work you hereby accept the Terms. Non-commercial uses of the work are permitted without any further permission from Dove Medical Press Limited, provided the work is properly attributed. For permission for commercial use of this work, please see paragraphs 4.2 and 5 of our Terms.

Download Article [PDF]  View Full Text [HTML][Machine readable]