Research supports safety, feasibility of sexual behaviour-based screening


Tuesday, June 21, 2022 Dr. Geraldine Walsh

Canadian Blood Services is committed to making blood donation as inclusive as possible while maintaining the safety of the blood supply. To this end, by September 30, 2022, we will be removing the current three-month time-based deferral specific to men who have sex with men and will implement sexual behaviour-based screening criteria for all donors, regardless of gender or sexual orientation, for all blood collection types. 

This change was made possible by a successful submission to our regulator, Health Canada, built on a solid bedrock of Canadian and international research. Among the findings that supported the submission were two recent studies from Canadian Blood Services. Together with other research evidence, these studies contributed findings that supported the safety and feasibility of this new approach to donor screening.  

How was safety affected by previous changes to eligibility criteria? 

The first study was led by Canadian Blood Services epidemiologist Dr. Sheila O’Brien and looked at the residual risk of HIV — that is, the remaining risk of infection per million donations — in the blood supply. The study assessed trends in this risk over the past decade, a timeframe spanning three changes to donor eligibility criteria that affect sexually active men who have sex with men: the change from an indefinite deferral to a 5-year deferral (2013), then to a 12-month deferral (2016), and then to the current 3-month deferral (2019). The results showed no increase in the residual risk of HIV with progressively shorter time-based deferrals for sexually active men who have sex with men. These results provided important supporting evidence that helped evaluate safety when considering the change to sexual behaviour-based screening. 

Read the Research Unit: Risk of HIV did not change with expanding eligibility criteria for gay, bisexual and other men who have sex with men

Will donors understand and accept sexual behaviour-based questions? 

The second study was led by Canadian Blood Services scientist Dr. Jennie Haw. It assessed the feasibility of implementing sexual behaviour-based screening questions by exploring how donors understand proposed alternative sexual behaviour-based screening questions; how acceptable they think the questions are; and how comfortable they feel answering them. The results indicated that most donors are likely to find sexual behaviour-based screening questions understandable and acceptable and feel comfortable answering them. Despite this, the findings suggest that Canadian Blood Services should consider ways to enhance donors' understanding and comfort level — for example, by adding a short explanation to the questionnaire before sexual behaviour-based questions are asked and providing donors with information about terms/words used. This study showed that sexual behaviour-based screening is feasible from the perspective of donors, and the results are informing Canadian Blood Services’ implementation plans. 

Read the Research Unit: Sexual behaviour-based screening questions: Understanding and mitigating donor discomfort

Learn more about Canadian Blood Services-supported research on donor eligibility criteria 

With funding from Health Canada, Canadian Blood Services is supporting 19 independent research projects to help inform more inclusive eligibility criteria for blood donation.  


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 healthcare 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. Find out more about our research impact.

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.

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