Dear List, please forgive this question from a hobby statistician, but I was wondering if there is any way of doing power calculations to estimate how much data is needed so that the sensitivity/specificity values along a ROC curve will be within a certain confidence interval? I am not aware of any such method, but was recently asked how much data would be needed to perform ROC analysis for a study. Thanks a lot, Peter Dr. med. Peter Robinson, MSc. Institut f?r Medizinische Genetik Universit?tsklinikum Charit? Humboldt-Universit?t Augustenburger Platz 1 13353 Berlin Phone: ++49-30-450 569124 Fax: ++49-30-450 569915 peter.robinson at charite.de http://www.charite.de/ch/medgen/robinson