MEASURING SEVERITY OF PSORIASIS - METHODOLOGICAL ISSUES

A validated measure of psoriatic severity is needed for effective trea tment and research of the disease, The absence of such a measure has l ed many investigators to create their own methods of assessing psorias is, while many others use such popular measurement techniques as the p soriasis area and severity index (PASI), Though few studies have been conducted to investigate the accuracy and usefulness of the PASI, inve stigators worldwide continue to use it in the evaluation of treatment, Investigators in the psychological sciences use an established set of measurement criteria (referred to as psychometrics) to evaluate and m odify scales that measure psychological constructs, However, these sam e criteria also can be utilized in determining how well the PASI, as w ell as the various other methods of psoriatic assessment, measure seve rity, In this paper, the scale of properties of validity and reliabili ty are discussed, including a review of the research addressing these properties within the PASI, Finally, a discussion of the future resear ch needed in the assessment of psoriasis is provided.