How to validate outcome instruments for pemphigus

Abstract

In this issue, Rosenbach et al. assess the reliability and validity of outcome instruments for pemphigus. Although the authors address the need for validated tools for use in therapeutic trials, the outcome instrument has been evaluated using data from only 15 selected pemphigus patients. Moreover, important steps in the validation process, such as sensitivity to change and construct validity, are not reported. Here, we discuss the methodological aspects of instrument assessment. © 2009 The Society for Investigative Dermatology.