JAMA Netw Open

Ferritin: What’s the best cut-off?

August 20, 2024

Ferritin cutoffs of 30 and 45 ng/mL were linked with substantially higher incident diagnoses of iron deficiency compared with a 15 ng/mL cutoff—especially in nonanemic patients—in this retrospective cohort study of primary care patients. Authors note that some patients with systemic inflammation may have elevated ferritin levels independent of iron stores.

• This retrospective cohort study included 255,351 adults (median age, 52 years; 52.1% female) who saw at least one general practitioner participating in the Family Medicine Research EMR Swiss research project from 2021 to 2023.
• Iron deficiency diagnosis incidences per 1,000 patient-years by ferritin cutoff were 15 ng/dL: 10.9; 30 ng/dL: 29.9; and 45 ng/dL: 48.3 cases.
• For nonanemic patients, iron deficiency diagnosis incidences per 1,000 patient-years were 4.1, 14.6 and 25.8 cases for the three thresholds, respectively.
• For anemic patients, iron deficiency diagnosis incidences per 1,000 patient-years were 3.5, 6.0 and 7.5 cases for the three thresholds, respectively.

Source:

Jäger L, et al. (2024, August 1). JAMA Netw Open. Ferritin Cutoffs and Diagnosis of Iron Deficiency in Primary Care. https://pubmed.ncbi.nlm.nih.gov/39102268/