engleski

Photovalidation of Two Outcome measure Instruments for Pemphigus

Multicenter controlled trials for pemphigus lack validated disease activity scoring systems. The reliability and convergent validity of the PDAI (pemphigus disease area index) has been previously validated with live patients. Here, we assess the reliability of the PDAI and the ABSIS (autoimmune bullous skin disorder intensity score) instrument using photographs. A group of 10 dermatologists scored photographs of 19 patients with pemphigus to determine the inter- and intra-rater reliability of the PDAI and the ABSIS. The inter-rater reliability(ICC) is 0.65 [95%CI:.49 - .82] for the ABSIS and 0.65[.49-.82] also for the PDAI. When reanalyzed excluding the most severe patients, the ICC was 0.52[.31 - .74] for the ABSIS and 0.58[.38 -.78] for the PDAI. The tools differed most in reliability of assessing skin activity, with an inter-rater ICC of 0.71[.55-.88] for the ABSIS and 0.52[.31 - .74] for the PDAI when severe patients were excluded from analysis. Intra-rater test-retest reliability demonstrated an ICC of 0.95[.90 - .99] for the ABSIS and 0.89[.79 - .98] for the PDAI. When data was reanalyzed excluding the most severe patients, the intra-rater ICC of 0.92[.84 - 1.00] was calculated for the ABSIS and 0.82[.66 - .98] for the PDAI. We conclude that evaluation by photographs are not as reliable as in person evaluation when using a standardized instrument. Given the large differences between live and photo results, it is not possible to conclude which instrument is better for more severe disease. Clearly in-person studies in the context of a larger range of disease activ¬ity are needed to assess this completely.

Photovalidation; multicenter controlled trials; pemphigus disease area index

nije evidentirano