The reticulocyte count is used to estimate the degree of effective erythropoiesis, which can be reported as absolute reticulocyte count or as a reticulocyte percentage. In general, reticulocytes mature within one day of being released from bone marrow; however, in the setting of stress erythropoiesis, as in a high erythropoietin level (eg, in persons with severe anemia), reticulocytes are prematurely released from bone marrow to the blood circulation, increasing the number of days that reticulocytes stay in the blood circulation (maturation time of reticulocytes in days) and resulting in a spuriously high reticulocyte count. The reticulocyte index, or reticulocyte production index, is a calculation that helps to alleviate the effect of the premature release of reticulocytes by taking into account maturation time of reticulocytes (ie, correction factor), in addition to correcting for the degree of anemia.

Absolute Reticulocyte Count and Index is a mobile app designed to help medical practitioner to calculate absolute reticulocyte count and reticulocyte index. Increased reticulocyte count reflects ongoing or recent red blood cell (RBC) production activity. A decreased reticulocyte count reflects decreased red blood cell (RBC) production. The reticulocyte index, or reticulocyte production index (RPI), which is corrected or adjusted for both premature release of reticulocytes from the bone marrow and the degree of anemia, is another parameter that provides an assessment for adequate bone marrow response to anemia. All calculations must be re-checked and should not be used alone to guide patient care, nor should they substitute for clinical judgment