Number needed to treat and cost of recombinant human erythropoietin to avoid one transfusion-related adverse event in critically ill patients.

OBJECTIVE To calculate the absolute risk reduction of transfusion-related adverse events, the number of patients needed to treat, and cost to avoid one transfusion-related adverse event by using erythropoietin in critically ill patients DESIGN Number needed to treat with sensitivity analysis. SETTING Teaching hospital. PATIENTS Hypothetical cohort of critically ill patients who were candidates to receive erythropoietin. INTERVENTIONS Using vs. not using erythropoietin to reduce the need for packed red blood cell transfusions. MEASUREMENTS AND MAIN RESULTS We used published estimates of known transfusion risks: transfusion-related acute lung injury, transfusion-related errors, hepatitis B and C, human immunodeficiency virus, human T-cell lymphotropic virus, and bacterial contamination, stratified by severity. Based on the estimated risk and frequency of transfusions with and without erythropoietin, we calculated the absolute risk reduction of transfusion-related adverse events, the number needed to treat, and cost to avoid one transfusion-related adverse event by using erythropoietin. The estimated incidence of transfusion-related adverse event was 318 permillion units transfused for all transfusion-related adverse events, 58 per million for serious transfusion-related adverse events, and 21 per million for likely fatal transfusion-related adverse events. The routine use of erythropoietin resulted in an absolute risk reduction of 191 per million for all transfusion-related adverse events, 35 per million for serious transfusion-related adverse events, and 12 per million for likely fatal transfusion-related adverse events. The number needed to treat was 5,246 to avoid one transfusion-related adverse event, 28,785 to avoid a serious transfusion-related adverse event, and 81,000 for a likely fatal transfusion-related adverse event. The total cost was $4,700,000 to avoid one transfusion-related adverse event, $25,600,000 to avoid one serious transfusion-related adverse event, and $71,800,000 to avoid a likely fatal transfusion-related adverse event. The magnitude of these results withstood extensive sensitivity analysis. CONCLUSIONS From the perspective of avoidance of adverse events, erythropoietin does not appear to be an efficient use of limited resources for routine use in critically ill patients.