What if the shelf life of red blood cells was less than 42 days?
What is this research about?
Since the 1970s, Canadian regulatory standards have imposed a maximum shelf life of 42 days for red blood cells (RBC) to ensure quality of the transfused product. Recently, some studies have suggested that patients transfused with “older blood”, blood that is closer to outdating, may have a poorer health outcome.
The shelf life of red blood cells could be shortened from 42 to 21 days without significantly affecting hospital or blood product supply chains. Hospitals that use large amounts of red blood cells would see less of an impact than smaller hospitals.
Below 21 days, there would be significant increase in red blood cells outdates and shortages.
The exact reason why remains unclear and further research is needed to confirm these results. We are left to ponder: What if the shelf life of RBCs was shortened? How would it affect the RBC supply chain? Because blood is perishable, managing inventory is complex. Indeed, ordering decisions depend not only on the stock that is available but also on its age.
What did the researchers do?
For this study, the researchers built a computer simulation model to evaluate the impact of shorter RBC shelf life. The computer model simulated the inventory and ordering behaviour of hospitals and blood suppliers as well as the demand for RBC by patients. The research team focused on systemic impact of; outdates (RBC units that would be too old to be transfused), shortages (instances when no RBC would be available for transfusion) and ordering behaviour (orders placed by the hospitals to the blood supplier). The model included data from blood supply centres in Montreal and Québec City as well as 97 hospitals throughout the province that account for more than 80 per cent of provincial demand. Once validated, the computer model was used to estimate the number of outdates, shortages, and emergency orders placed by hospitals if the shelf life of RBC was shortened from 42 days to 14 days in increments of seven days.
What did the researchers find?
Shortening the RBC shelf life from 42 days to 28 or 21 days did not result in large increases in system wide outdates, shortages, or emergency orders. However, reducing it to below 21 days resulted in large increases in either outdates or shortages or both.
The impact of a shorter shelf life differentially affected hospitals of differing sizes; with larger hospitals seeing less of an impact in terms of the rate of shortages or outdates, than smaller hospitals.
Shortening the shelf life of RBC placed increased pressure on Group O blood, particularly as shelf life is reduced below 21 days.
How can you use this research?
This study provides information to guide the implementation of a shorter RBC shelf life policy, should more evidence be found to confirm that transfusion of “older blood” leads to poorer patient outcomes. As the shelf life of RBC is decreased, managing inventory at both hospital and blood supplier sites becomes more complex. This study suggests that decreasing shelf life of RBC from the current maximum of 42 days to 21 days would not significantly affect the blood supply. However, decreasing it to below 21 days would lead to substantial increases in both outdates and shortages at both hospitals and at supplier sites.
About the research team
Dr. John Blake is an Engineer at Canadian Blood Services and an Associate Professor in the Department of Industrial Engineering at Dalhousie University. His research interest is in the application of Operational Research techniques to health care problems. Mathew Hardy is a MASc student with Dr. Blake and a Canadian Blood Services technician. Dr. Gilles Delage is the Vice-President of Medical Affairs at Héma-Québec.Genevieve Myhalis a Business Analyst within Medical Affairs at Héma-Québec.
This research unit is derived from the following publication(s)
 Blake JT, Hardy M, Delage G, Myhal G (2013). Déjà vu all over again: The impact of shorter shelf life for red blood cells. Transfusion (Forthcoming).
Acknowledgements: This research received financial support from Canadian Blood Services Blood Research and Development Program funded by the federal (Health Canada), provincial and territorial Ministries of Health and by the Natural Sciences and Engineering Research Council (NSERC). The views expressed herein do not necessarily represent the view of the federal government. In-kind support was provided by Héma-Québec.
Keywords: Age of red cells, simulation modelling, logistics, inventory planning.