A-141 Ferritin Test Utilization to Differentiate Microcytic Anemia

Abstract

Abstract Background Mean corpuscular volume (MCV) of the Red Blood Cells (RBC) is a component test of the commonly ordered Complete Blood Count (CBC) panel and is an important parameter when evaluating a patient diagnosed with anemia. MCV is used to classify anemia as microcytic (low MCV), normocytic (normal MCV), or macrocytic (high MCV). Microcytic anemia occurs most commonly from iron deficiency or from an inherited blood disorder caused when the body does not produce enough hemoglobin (thalassemia trait), often resulting in iron overload. Clinical management for each of these microcytic anemia contributors varies greatly and requires appropriate differentiation. Laboratory testing of serum ferritin level helps to distinguish iron deficiency from thalassemia and is therefore the first laboratory test recommended in the evaluation of microcytosis. However, initial laboratory findings indicate that ferritin tests do not always accompany low MCV results. The objective of this study was to quantify the frequency of ferritin orders proximate to abnormally low MCV results across two hospitals to assess utilization of ferritin testing for differentiating microcytic anemia. Methods A retrospective study was performed on the ordering patterns of MCV and ferritin tests at two different hospitals. Abnormally low MCV values were selected from both adult and pediatric populations during an eight-month period from March through October. All ferritin values from January through December of that same calendar year were selected and joined with the MCV data. Patients with a ferritin test 60 days before or after the MCV test were considered to have a ferritin order associated with the abnormally low MCV. The ratio of the total count of these ferritin orders to the total count of low MCV values was calculated as a percent. Results Results showed that 46% (619/1351) of all abnormal low MCV values at Hospital One (Pediatric) had a ferritin ordered within 60 days. An additional 57 cases had a ferritin ordered beyond 60 days, and 675 lacked ferritin orders during the calendar year. During that same period and using the same criteria, Hospital Two (Adult) had ferritin ordered 43% (2301/5320) of the time. An additional 135 had a ferritin ordered beyond 60 days, and 2884 lacked ferritin orders during the calendar year. Conclusions Establishing test utilization benchmarks can be a useful stewardship tool for clinical laboratories. The data presented here suggested an underutilization of ferritin testing in the presence of abnormally low MCV values across two healthcare organizations. This study lays the groundwork to further assess MCV and ferritin ordering patterns and a standardized means to quantify these observations across diverse healthcare settings to establish a more robust benchmark.