Sensitivity and Specificity of Diagnostic Algorithms of Preoperative Anemia

Preoperative management of anemia is one of the pillars of patient blood management. Diagnostic algorithms developed to support an anemia diagnosis have not yet been validated. The aim of this study was to validate and compare three commonly used diagnostic algorithms for preoperative anemia.We performed a prospective diagnostic study to detect the types of anemia present and compare the specificity and sensitivity of three diagnostic algorithms for preoperative anemia in patients scheduled to undergo major abdominal surgery. We used Cohen κ to compare the interrater reliability (agreement) of the diagnostic anemia algorithms with its standard reference.Of the 10 tested types of anemia, six had a prevalence of >10% in the studied patients, namely iron deficiency, vitamin B12 deficiency, anemia of chronic disease, renal anemia, thyroid-related anemia, and anemia of bleeding. The Network for the Advancement of Transfusion Alternatives algorithm had substantial agreement with the standard reference for renal anemia but performed less appropriately for the other types of anemia. The Society for the Advancement of Blood Management algorithm displayed moderate agreement with the standard reference for deficiency of iron and B12 and for renal anemia and had substantial agreement detecting anemia of bleeding, whereas the other types of anemia were detected less appropriately. The Institute for Blood Management, Gotha, Germany algorithm had a moderate agreement with the standard reference for anemia of bleeding and near perfect agreement for all other types of anemia.We were able to show that the diagnostic anemia algorithm of the Institute for Blood Management, Gotha, Germany is superior to those of the Network for the Advancement of Transfusion Alternatives and the Society for the Advancement of Blood Management in its ability to detect the six common types of preoperative anemia in patients scheduled to undergo abdominal surgery, the presence of multiple types of anemias in a given patient, and its ability to detect rare anemias that have a clinical implication for management.