Why test iron panel?
Iron panel has low sensitivity for iron deficiency. It’s really only abnormal when iron is significantly low.
Ferritin has much higher sensitivity.
Ferritin is an acute phase reactant. Sure it can be falsely elevated sometimes but I think it is still far superior to iron panel. By the time iron panel shows iron deficiency, I can usually tell by seeing their microcytic anemia anyway.
I used to check iron panels with ferritin and over time I found that it never changed assessment or management. Now I just check ferritin with an ESR/CRP.
Would like to hear your thoughts.
Update:
Lots of helpful responses here, I am learning a lot. I should have specified that in my field, pre-test probability is very low and I am using ferritin as the primary screening tool. It just doesn’t make sense for me to order an additional iron panel on every patient because most of the time it will be normal. This algorithm is probably more specific to my field.
It makes more sense if you are in hematology or managing anemia since you’re probably ordering 10 other labs and an extra iron panel doesn’t add much.
I am still not entirely sure if the iron panel itself is helpful since if you are doing a full work up, sTfR or hepcidin will detect ACD better anyway.