Figure 2: Relationship between Psoriasis Area and Severity Index (PASI) and Simplified PASI (SPASI) scores

            PASI and SPASI scores were calculated for 1000 simulated patients in each of population 1 (A) and population 3 (B).  Both populations show a strong correlation between PASI and SPASI scores.  A key use of the SPASI would be to identify subjects whose PASI scores are above a criterion for severe disease, for example PASI>12.  Grey areas show discordant values where PASI>12 and SPASI<12 or PASI<12 and SPASI>12)