I need some urgent advice for a grant application. I am evaluating a new diagnostic test and at the last minute a Professor has offered me the dataset from a completed prospective study of the disease my test diagnoses. He wants me to check if his data is adequately powered to achieve and AUC of 0.75.
The cohort is n=318 and the prevalence of the disease is 50%.
Can this be done - is it scientifically sound? Does this qualify as post-hoc power calculation?