OPGA a Valuable Tool for Assessing Psoriasis Severity

plaque psoriasis on chest
plaque psoriasis on chest
Researchers aimed to assess the validity of the overall provider global assessment (OPGA) and patient-reported global assessment (PtGA) as feasible measures of psoriasis for use in routine clinical practice.

Overall provider global assessment (OPGA) is an effective assessment tool for psoriasis severity that can be used in daily clinical practice, investigators reported in a study published in the Journal of the American Academy of Dermatology.

Researchers aimed to assess the validity of the OPGA and patient-reported global assessment (PtGA) as feasible measures of psoriasis for use in routine clinical practice.

The study authors’ psoriasis specialty clinic at the University of Utah determines OPGA by considering the plaque PGA (PPGA), body surface area (BSA), and body location, and then assigning a score from clear to very severe (0-5). To determine PtGA, patients rate their disease severity during the past week using an 11-point scale (0 = no psoriasis symptoms; 10 = worst-ever psoriasis symptoms).

All patients 18 years of age or older with chronic plaque psoriasis observed at the clinic from September 2015 to March 2018 were included if they were prescribed oral systemic medication, a biologic agent, or phototherapy and were not receiving therapy other than topicals at their baseline visit.

The researchers assessed clinical data from 162 participants (median age, 40 years; 51.9%  women; 78.4% White) from the electronic medical records of 432 visits. The patients had a median duration of psoriasis of 9 years (interquartile range [IQR], 2-20). A majority (54.3%) of the cohort had a moderate OPGA score (3) at baseline, and the median patient-reported severity score at baseline was 8 (IQR, 5-10).

The investigators evaluated validity with use of PPGA × BSA as the standard (criterion validity) and responsiveness of the measures with use of Spearman correlations. The intraclass correlation coefficient was used to measure inter-rater reliability.

Physician-reported measures were documented by 2 raters on the same patients during the same visits.

The strongest correlation was found between OPGA and PPGA × BSA, with a similar trend over time (r > 0.71). OPGA also was correlated strongly with baseline and follow-up BSA (r > 0.55) and PPGA (r > 0.63). OPGA was responsive to changes in severity over time (change in OPGA by change in PPGA × BSA, r > 0.80). Inter-rater reliability for OPGA was high (intraclass correlation coefficient = 0.89 [95% CI, 0.60-0.97]).

The investigators found that PtGA was not well correlated with either OPGA (r = 0.41) or PPGA × BSA (r = 0.43) at baseline. The correlations improved somewhat during follow-up visits but were still consistently less correlated (r < 0.6) compared with other physician-reported measures (ie, PPGA and BSA).

“The relative simplicity of OPGA, high correlation with PPGA × BSA, and more informative assessment of disease impact relative to other psoriasis measures make OPGA an ideal single assessment tool for use in daily clinical practice,” stated the researchers. “However, OPGA does not negate the need to capture patient-reported outcomes given the lower correlations between the 2.”

Disclosure: One of the study authors declared affiliations with pharmaceutical companies. Please see the original reference for a full list of authors’ disclosures.


Taliercio V, Langner AU, Secrest AM, Duffin KC. Assessing psoriasis severity: psychometric validation of overall physician global assessment. J Am Acad Dermatol. 2022;86(3):637-638. doi:10.1016/j.jaad.2021.01.014