How accurate of an indicator is reticulocyte hemoglobin equivalent for iron deficiency?

I am not sure that question is answerable right now. I can tell you if I had an autoanalyzer with a RET-He, I would use it to determine who needs iron and who does not using a value of 30.7 as the cutoff for iron deficiency and 28.5 to determine the likelihood of responsiveness to iron [remember tha...