classification performance metric for high risk medical decisions What is the best classification performance metric for risky medical treatments like surgery? for example a patient should NOT suggest a surgery (negative) if he/she can be treated by medicine (positive). Does Negative predictive value (TN/TN+FN) works for this situation?
Check ROC curve, increase the threshold and measure PPV.
Also you can not use only one in isolation, you have to check sensitivity, specificity and PPV in order to understand the complete scenario.