How Do Ferritin Cutoffs Affect Diagnosis Rates?

TOPLINE:

Ferritin cutoffs of 30 and 45 ng/mL are linked to higher iron deficiency diagnosis rates than a cutoff of 15 ng/mL in patients with nonanemia and anemia.

METHODOLOGY:

• Researchers used data from the Family Medicine Research Using Electronic Medical Records (FIRE) project in Switzerland for patient analysis.
• A total of 255,351 patients aged 18 years or older with at least one consultation from 2021 to 2023 were included in the study.
• Ferritin cutoffs of 15, 30, and 45 ng/mL were used to define iron deficiency events for both patients with anemia and nonanemia, with patient-time calculated from inclusion to the earliest iron deficiency event or end of the study period.
• The analysis included sex, age, clinical patient profiles, and professional general practitioner characteristics.

TAKEAWAY:

• Ferritin cutoffs of 30 and 45 ng/mL were associated with higher incidences of iron deficiency diagnosis than a cutoff of 15 ng/mL.
• Nonanemic iron deficiency diagnoses had incidences of 4.1, 14.6, and 25.8 cases per 1000 patient-years at ferritin cutoffs of 15, 30, and 45 ng/mL, respectively.
• Anemic iron deficiency diagnosis had incidences of 3.5, 6.0, and 7.5 cases per 1000 patient-years at ferritin cutoffs of 15, 30, and 45 ng/mL, respectively.

IN PRACTICE:

“Ferritin cutoffs of 30 and 45 ng/mL were associated with a substantially higher incidence of iron deficiency compared with 15 ng/mL,” wrote the authors of the story. “These results provide a basis for health system-level evaluation and benchmarking of ferritin testing in high-resource settings and call for a harmonization of diagnostic criteria for iron deficiency in primary care.”

SOURCE:

The study was led by Levy Jäger, MD, of the Institute of Primary Care at the University Hospital Zurich in Zurich, Switzerland, and published online on August 5 in JAMA Network Open.

LIMITATIONS:

Researchers had little access to details surrounding gastrointestinal risk factors or diet information. Researchers had no access to the presenting symptoms of patients through FIRE.

DISCLOSURES:

No disclosures were reported.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.