Data dig uncovers associations between donor characteristics and patient outcomes

While blood transfusion is safer now than ever before, scientists continue to look for ways to reduce risk and ensure the healthiest possible outcomes for patients.

A unique collaboration between Canadian Blood Services, The Ottawa Hospital and Université Laval has led to some interesting and somewhat unexpected findings that open the door to new areas of research in transfusion medicine.

Press release: Researchers find unexpected association between younger donor age, female sex and transfusion outcomes

Although the blood collection and red blood cell preparation processes are standardized, there are inherent differences in every red blood cell unit because each one comes from a unique, individual donor. 

This study sought out to uncover associations between certain donor characteristics and patient outcomes. The findings have generated new research questions that will help us better understand “what’s inside the bag”.  

The research

This study linked large databases of patient data with red blood cell donor records to see if donor characteristics (age and sex) had an impact on recipient outcome.

Dr. Dean Fergusson, a senior scientist at The Ottawa Hospital and Dr Michaël Chassé, a critical care physician at CHU de Québec Université Laval, established large transfusion patient databases that included data from The Ottawa Hospital Data Warehouse and the Institute for Clinical Evaluative Sciences (ICES).

In collaboration with Dr. Jason Acker, senior development scientist at Canadian Blood Services, these datasets were linked to blood donor data to retrospectively investigate the impact of donor characteristics like sex and age on transfusion patient outcomes.

For this study, the researchers were able to link 30,503 transfusion recipients at The Ottawa Hospital (from Oct. 2006 to Dec. 2013) with their respective blood donors (80,755 donors in total). The findings of their investigation were published this week in JAMA Internal Medicine.

Full reference: Michaël Chassé, Alan Tinmouth, Jason P Acker, Shane W English, Kumanan Wilson, Greg Knoll, Nadine Shehata, Carl van Walraven, Lauralyn McIntyre, Alan Forster, Tim Ramsay, Dean Fergusson. (2016). Association of blood donor age and sex with recipient survival after red blood cell transfusion. JAMA Internal Medicine. July 11, 2016

The findings

The researchers found that recipients of female donor red blood cells were associated with poorer outcomes. They also found similar associations with red blood cells from younger donors.

“We need further research to confirm these findings and to look at possible biological mechanisms,” said lead author Dr. Michaël Chassé, an assistant professor at Université Laval and a critical care physician at CHU de Québec Université Laval. “One possibility is that components in the blood of younger donors or female donors may affect the immune system of the transfusion recipient.”

It’s important to note that these are associations only  no cause and effect has yet been found. And, further investigation must be done to confirm and understand what these findings mean.

 “Though our research suggests that we should investigate what’s behind the associations that we found, there is no definitive evidence yet that proves that one type of blood is better or worse for patients,” says Dr. Jason Acker. “However, this study opens up exciting new areas of investigation where we can really dig into the biological explanations and understand true cause and effect. In the meantime, patients continue to receive the safest transfusions possible.”

The ability to link donor characteristics with patient outcomes has the potential to radically change how clinical practice is informed by research and large data analytics.  A similar big data dig, in collaboration with Dr. Nancy Heddle at McMaster University, found some associations between manufacturing processes and patient outcome.

Next steps

Now that the researchers have identified these interesting associations, they can take an even more detailed look at the factors and figure out the biological mechanisms behind the findings.

Follow-up studies are planned, including continued analysis, data verification and validation. If warranted, clinical trials may be necessary to definitively examine the role of donor characteristics on patient outcomes.

The ability to link donor and product characteristics to patient outcomes was thanks to investments in research funding by Canadian Blood Services, the federal government (Health Canada), the provincial and territorial ministries of health and the Canadian Institutes of Health Research.This work was made possible through extensive collaboration between Canadian Blood Services, the Ontario Institute for Clinical Evaluative Sciences and The Ottawa Hospital Data Warehouse.

Further reading:

Data mining 2: Digging for deeper understanding of donors and transfusion outcome

Canadian Blood Services – Driving world-class innovation

Through discovery, development and applied research, Canadian Blood Services drives world-class innovation in blood transfusion, cellular therapy and transplantation—bringing clarity and insight to an increasingly complex health-care future. Our dedicated research team and extended network of partners engage in exploratory and applied research to create new knowledge, inform and enhance best practices, contribute to the development of new services and technologies, and build capacity through training and collaboration.

The opinions reflected in this post are those of the author and do not necessarily reflect the opinions of Canadian Blood Services nor do they reflect the views of Health Canada or any other funding agency.