We recieved the reviewer comment as follow:
to confirm the utility of the cut-off value, validation would be needed. However, in this cohort, validation analysis was not performed. As the sample size was small, it would be difficult to perform external validation study. however, internal validation (or cross-validation) analysis might be able by statistical methods such as leave-one-out or k-fold cross-validation methods.
I could not undersand statistical method which reviewer intend.
Could you solve this problem by JMP?
