Iron Deficiency: We Think We Know It All!
Authors: Moss Arianna S , Thomas Melissa , Gibson Spencer , Quy Ray , Zhao Eva , Wang Angelina , Debeusscher Ben P , Pakbaz Zahra 
Published: December 2024

Background:
Iron deficiency (ID) is the most pervasive nutritional deficiency, with current studies estimating it to affect over 1.2 billion people globally [1]. Although anemia is the most widely understood consequence of ID, ID is also the underrecognized cause of white blood cell and platelet count abnormalities.Early recognition of ID is crucial, as ID can be a prodrome of malignancy, exacerbate chronic conditions, and lead to decreased quality of life. However, among health care professionals, there are several misconceptions regarding the clinical presentation and diagnosis of ID, leading to delayed or missed diagnoses of ID. The primary objective of the current study is to assess physician knowledge gaps in diagnosing ID.
Methods:
This study is a retrospective chart review of 862 adults (mean age +/- SD of 52.9 ± 18.4, 497 female) seen by a classical hematologist between February 2020 and July 2023 in a new single-provider clinic for adults with non-cancer blood disorders within the division of hematology oncology at an academic center. Data analysis included specialty type of referring provider, referral reason or diagnosis, and the diagnosis made by the consulting adult classical hematologist in this clinic. ID was defined as a serum ferritin level &lt;30 mg/L or &lt;100 mg/L in the presence of inflammatory comorbidities. Red cell indices also aided in the diagnosis when appropriate.
Results:
Out of 862 patients seen, there were 202 referrals for anemia, 7 referrals for ID (without anemia), 14 referrals for neutrophilia, 84 referrals for neutropenia, 84 referrals for thrombocytopenia, and 24 referrals for pancytopenia. In this clinic, undiagnosed ID was found to be the primary etiology or contributory cause of the hematologic abnormality in 194 of the referrals analyzed. Undiagnosed ID was discovered to be the sole etiology for 38.1% of anemia referrals, 71.4% of neutrophilia referrals, 9.5% of neutropenia referrals, 6% of thrombocytopenia referrals, and 4.2% of pancytopenia referrals. Of these referrals, 50.0% were from primary care physicians (IM and FM), 40.7% were from specialty clinics, and 9.3% were self-referred. Additionally, ID was found to be a contributory cause of 14.9% of anemia referrals, 35.7% of neutropenia referrals, 25% of thrombocytopenia referrals, and 20.8% of pancytopenia referrals. Of these referrals, 40.7% were from primary care physicians, 52.3% were from specialty clinics, and 7.0% were self-referred.
Conclusion:
This analysis demonstrates that diagnosing iron deficiency (with or without anemia) is a challenge for first-contact physicians, both in primary care and specialty clinics, and may easily be missed. This leads to delays in iron deficiency treatment and resulting clinical consequences. Educational interventions are necessary to improve healthcare providers' skills for early diagnosis of iron deficiency. Given the shortage of classical hematologists, this intervention may also allow for the allocation of classical hematology clinic appointments to more complex classical hematology referrals.
Citations:
1. Camaschella C. Iron deficiency. Blood. 2019 Jan 3;133(1):30-39. doi: 10.1182/blood-2018-05-815944. Epub 2018 Nov 6. Erratum in: Blood. 2023 Feb 9;141(6):682. doi: 10.1182/blood.2022018610. PMID: 30401704.