The global blood donation index: an imperfect measure of transfusion need

The optimal number of units of blood and the associated number of blood donors that are required to meet the needs of a given population remains undetermined. It is frequently quoted that, at a minimum, a whole blood donation rate of 10 donations per 1000 population is necessary to meet a country’s blood needs. This is attributed to a recommendation by the World Health Organization (WHO) that 1% of the population must donate blood to ensure that there is a sufficient blood supply to meet clinical needs. This often-cited metric was first referenced in a 1971 WHO report; neither supporting data nor references were provided, suggesting that it was flawed at its founding. Regardless, it does not provide an accurate, contemporary determination of blood needs. This has ramifications for health service provision and planning, particularly in low- and lower-middle-income countries. Modeling studies that account for geographic variability in disease burden, healthcare infrastructure, and transfusion practices are needed to accurately estimate blood needs. A paucity of data to inform modeling remains a major obstacle in this regard. We discuss the history of the global blood donation index and highlight some factors that should be considered to better understand contemporary blood needs.