Inconsistency in ferritin reference intervals across laboratories: a major concern for clinical decision making.

Area of Science:

• Clinical Chemistry
• Hematology
• Laboratory Medicine

Background:

• Iron deficiency anemia is a global health issue.
• Diagnosis relies on hemoglobin and plasma ferritin levels.
• Variability in ferritin testing impacts diagnosis accuracy.

Purpose of the Study:

• Investigate variability in ferritin reference intervals across Dutch laboratories.
• Examine the effect of this variability on identifying iron-related disorders.

Main Methods:

• Collected ferritin reference intervals from 52 Dutch labs.
• Analyzed ferritin, hemoglobin, and MCV data from 397,548 healthy patients across four platforms.
• Assessed abnormal ferritin measurement variations using GP data from 3,699 patients.

Main Results:

• Median ferritin levels varied significantly by sex, age, and laboratory platform.
• Wide differences in ferritin reference intervals were observed, even within the same platform.
• This variability led to substantial differences in classifying abnormal ferritin measurements, affecting diagnosis rates.

Conclusions:

• Lack of harmonization in ferritin assays and reference intervals hinders accurate iron status interpretation.
• Standardization of ferritin assays and uniform reference intervals are essential.
• Harmonization will reduce variability in clinical interpretations and improve iron disorder diagnosis.