THE SELF-ADMINISTERED PSORIASIS AREA AND SEVERITY INDEX IS VALID AND RELIABLE

The self-administered psoriasis area and severity index (SAPASI) is a structured instrument for measuring the severity of psoriasis. This st udy examines the validity, reliability, and responsiveness of the SAPA SI, Trained personnel performed a psoriasis area and severity index (P ASI) assessment on the same day a SAPASI was obtained from 80 subjects . The validity of the SAPASI was demonstrated using the PASI as the st andard (r(2) = 0.59, p = 0.0001). Significant correlations were found between SAPASI and PASI for body surface area (r = 0.62-0.75), erythem a (r = 0.39), induration (r = 0.24) and scale (r = 0.38). Test-retest reliability was assessed in 19 subjects with repeated evaluations with in 2 d, Correlations between the first and second SAPASI scores (r = 0 .82) were highly significant (p = 0.0001), Inter-rater reliability of SAPASI body surface area measurements among five raters was very high (intraclass correlation coefficient R = 0.953). The SAPASI was respons ive to changes in severity over time as demonstrated by correlation wi th changes in PASI scores (r 0.63, p = 0.0002), We conclude that this structured patient self-report instrument facilitates quantitative ass essment of psoriasis.