Diagnosing iron deficiency in a hospital population.

The iron status of four hundred and forty-seven hospital patients was studied in order to assess the efficiency of laboratory tests in diagnosing iron deficiency. One hundred and three patients (23%) were iron deficient on bone marrow examination. The laboratory tests had a low diagnostic efficiency, with either a low diagnostic rate or a high false positive rate. However, serum ferritin, despite a diagnostic rate of 25% did establish the diagnosis with near certainty, avoiding the need for invasive and costly investigations. Serum ferritin should be retained in the laboratory investigation of iron deficiency. Serum iron with iron binding capacity should be removed from the repertoir.