This simple mathematical check, often employed in laboratory settings, helps assess the internal consistency of a complete blood count (CBC). It involves comparing the hemoglobin, hematocrit, and red blood cell count. A consistent CBC typically demonstrates a predictable relationship between these three parameters: the hematocrit should be approximately three times the hemoglobin, and the red blood cell count multiplied by three should roughly equal the hemoglobin. For example, a hemoglobin of 15 g/dL should correspond to a hematocrit near 45% and a red blood cell count around 5 x 10^6/L. Deviations from these expected relationships may suggest analytical errors or point towards specific underlying hematological conditions.
This quick validation method aids in quality control by flagging potential inaccuracies in CBC results, enabling prompt investigation and preventing misdiagnosis. It offers a readily available tool for clinicians and laboratory professionals to ensure reliable hematological assessments, thereby contributing to improved patient care. While not a diagnostic tool in itself, this check has long served as a valuable first-line assessment for ensuring the validity of CBC data before further interpretation.