PGAxBSA composite versus PASI: Comparison across disease severities and as therapeutic response measure for Cal/BD foam in plaque psoriasis
Linda Stein Gold, Jes B. Hansen, Dharm S. Patel, Karen A. Veverka, Bruce Strober
Abstract
BackgroundThe product of the Physician Global Assessment and body surface area (PGA×BSA) is simpler to use than the Psoriasis Area and Severity Index (PASI), which lacks sensitivity in patients with mild psoriasis.ObjectiveTo compare the PGA×BSA versus the modified PASI (mPASI) for assessing disease severity and therapeutic response to calcipotriol/betamethasone dipropionate (Cal/BD) foam.MethodsThis post hoc analysis evaluated the efficacy of Cal/BD foam in mild, moderate, and severe psoriasis, as assessed by the PGA×BSA and mPASI, using data from 3 randomized controlled trials (NCT01536886, NCT01866163, NCT02132936). Spearman correlation and Bland-Altman plots were used to compare the PGA×BSA with the mPASI.ResultsProportions of patients receiving Cal/BD foam achieving 75% response for PGA×BSA and mPASI at weeks 1, 2, and 4 were similar and significantly greater than with vehicle (P ≤ .002 at all timepoints); at week 4, mean improvements were 51.0% and 50.7%, respectively. Spearman correlations for mild, moderate, and severe psoriasis were moderate to high between PGA×BSA and mPASI at baseline (r = .51, .72, and .86, respectively; n = 126, 465, and 58, respectively) and high at week 4 (r = .80, .81, and .89, respectively; n = 121, 452, and 58, respectively) (P < .001).LimitationsPooled data from different trials were not prespecified for post hoc analysis. Interrater reliability was not assessed.ConclusionPooled data analysis showed that the PGA×BSA and mPASI correlation was higher with increasing psoriasis severity. The product of the Physician Global Assessment and body surface area (PGA×BSA) is simpler to use than the Psoriasis Area and Severity Index (PASI), which lacks sensitivity in patients with mild psoriasis. To compare the PGA×BSA versus the modified PASI (mPASI) for assessing disease severity and therapeutic response to calcipotriol/betamethasone dipropionate (Cal/BD) foam. This post hoc analysis evaluated the efficacy of Cal/BD foam in mild, moderate, and severe psoriasis, as assessed by the PGA×BSA and mPASI, using data from 3 randomized controlled trials (NCT01536886, NCT01866163, NCT02132936). Spearman correlation and Bland-Altman plots were used to compare the PGA×BSA with the mPASI. Proportions of patients receiving Cal/BD foam achieving 75% response for PGA×BSA and mPASI at weeks 1, 2, and 4 were similar and significantly greater than with vehicle (P ≤ .002 at all timepoints); at week 4, mean improvements were 51.0% and 50.7%, respectively. Spearman correlations for mild, moderate, and severe psoriasis were moderate to high between PGA×BSA and mPASI at baseline (r = .51, .72, and .86, respectively; n = 126, 465, and 58, respectively) and high at week 4 (r = .80, .81, and .89, respectively; n = 121, 452, and 58, respectively) (P < .001). Pooled data from different trials were not prespecified for post hoc analysis. Interrater reliability was not assessed. Pooled data analysis showed that the PGA×BSA and mPASI correlation was higher with increasing psoriasis severity.