To the Editor.
—I agree with the opinion expressed by Crosby in the article entitled "Reticulocyte Counts," published in the December 1981 Archives (141:1747-1748) that the reticulocyte count is one of the best and most cost-effective means to detect anemia. I would like to suggest some additional considerations evoked by present technology that might apply to the conversion of the raw reticulocyte percentage to the reticulocyte production index.As pointed out by Crosby, the correction factor usually is expressed as the patient's hematocrit reading divided by an average or ideal hematocrit reading, usually 45%. Since the raw reticulocyte count is expressed as a percentage of the total number of RBCs, it is an attempt to correct for the decreased number of RBCs that is frequently present in anemic states. What one is interested in is not the percentage of cells that are reticulocytes, but rather how many reticulocytes the body
Shanahan MB. Reticulocyte Counts. Arch Intern Med. 1982;142(8):1585. doi:10.1001/archinte.1982.00340210183046