Clinicians may improve diagnostic accuracy for anemia by setting different serum ferritin thresholds depending on patient age and gender, according to research published in the American Journal of Hematology.
Researchers attempted to enumerate a more exact relationship between reference intervals of serum ferritin and iron deficiency based on patient age and gender.
Two cohorts of patients were included from Massachusetts General Hospital: the first, for an interpatient analysis, included data from 48,409 patients that were used to determine the optimal serum ferritin reference interval for correctly diagnosing iron deficiency, and the second, for an intrapatient analysis, included data from 10,042 patients that were used to determine what level of serum ferritin increase was necessary for an increase in red blood cell measurements.
Declines in the red cell index of about 5% were associated with a serum ferritin threshold range of 10 ng/mL to 25 ng/mL. These figures were, however, lower in younger women (18-45 years) compared with older women (60-95 years) and men.
Similar results were found for determining the threshold of serum ferritin increase necessary for a red blood cell measurement increase: younger women had lower thresholds (approximately 15 ng/mL) compared with older women (approximately 25 ng/mL) and men (approximately 35 ng/mL).
“We have presented a framework for functionally defining iron deficiency in adults, and we have used this framework to show that the most appropriate serum ferritin cutoffs for diagnosis of iron deficiency may vary by age and sex within adults, and with reference to the hematologic parameter of interest,” the researchers concluded.
1. Foy BH, Li A, McClung J, Ranganath R, Higgins JM. Data-driven physiologic thresholds for iron deficiency associated with hematologic decline [published online December 17, 2019]. Am J Hematol. doi:10.1002/ajh.25706