Objectives: This study aimed to develop a root cause analysis (RCA) model for test overutilization, applying it to transferrin overordering at our institution. Methods: A comprehensive review was undertaken to establish a systematic RCA model. Upon implementation, the questionnaire identifying the root causes of transferrin overordering with infographic intervention was distributed to clinicians and nurses. Results: The RCA model comprises 5 steps: (1) problem identification, (2) causal factor determination, (3) data collection, (4) significant factor identification, and (5) corrective action development and outcome measurement. The major causes of transferrin overutilization were confusion between transferrin and transferrin saturation, as well as unfamiliarity with the laboratory handbook. An infographic reduced postintervention transferrin ordering among clinicians (84.9%, P < .001) and nurses (46.8%, P < .001). Conclusions: This study presents a 5-step RCA model that offers a customized method to identify the causes of test overutilization. Applying this model to transferrin at our institution revealed 22 leading root causes. Laboratories are encouraged to adopt this RCA model as it can contribute to optimized patient care and more efficient resource allocation.
