Blood Collection Capacity Does Not Equal Available Blood
A blood system can expand collection capacity and still produce fewer successful donations. Four years of NHS Blood and Transplant data show where potential supply is lost before it becomes blood available for patients.
First, define the bottleneck correctly.
The distinction matters. A collection slot is potential supply. It becomes useful blood only if the pathway continues successfully through booking, attendance, donor eligibility, collection, testing, processing, inventory and distribution.
More available collection slots did not produce more successful donations.
Rahimi and colleagues analysed national NHSBT whole-blood collection activity from April 2022 to March 2026. Total collection capacity increased from 1,897,775 to 2,042,265 slots, an increase of 7.6%.
At the same time, successful donations decreased from 1,457,455 in 2022/23 to 1,407,546 in 2025/26, a decline of approximately 3.4%.
The 2025/26 appointment fill rate was 74.7%. Non-attendance remained between 9.1% and 10.4%. Deferral rates moved from 13.4% in 2022/23 to 16.8% in 2024/25, then improved to 14.4% in 2025/26.
Recruiting a donor is not the same as obtaining a successful donation.
First-time donors increased as a share of bookings, but their booking-to-successful-donation conversion averaged only 57.8%, compared with 78.4% for repeat donors.
The abstract reports higher losses among first-time donors through both non-attendance and post-attendance losses, including deferrals and failed venepunctures.
Each step has a role. Each step can also become a bottleneck.
Building the system is essential. It still does not remove every constraint.
This is why blood supply resilience cannot be measured only by the number of donors, donor centres or available collection slots. The operational task of a blood system is to convert potential donors and collection capacity into safe blood that is actually available when and where patients need it.
The NHSBT analysis is useful because it shows the gap inside a national collection system using real operational data. Expanding infrastructure remains important, but infrastructure alone does not guarantee functional blood availability.
How should health systems strengthen donor blood supply while also developing complementary options for time windows and locations where donor blood is unavailable, delayed or difficult to deploy?
Complement the blood system, not dismiss it.
Donor blood remains essential. The relevance to BHOC is the resilience question: whether a validated oxygen-delivery bridge could complement donor blood in specific settings where access, timing or logistics create a gap.
This page does not claim that BHOC can replace donor blood or solve donor-system attrition. It identifies a documented systems problem that can inform future research, product design and implementation studies.
Primary source
Rahimi N, Vendramin C, Fletcher A, Chia L. Challenges in Donor Recruitment and Donor Retention in NHSBT Whole Blood Collection: A Four-Year Analysis. Abstract P020. XLIII Annual Scientific Meeting of the British Blood Transfusion Society, SEC Glasgow, United Kingdom, 15-17 September 2026. Published in Transfusion Medicine, Volume 36, Issue S1. First published 11 September 2026.
Official BBTS 2026 abstract collection DOI: 10.1111/tme.70109
Wiley Online Library: Open official abstract collection ↗
Scientific and educational evidence analysis. The source describes blood collection operations and donor pathway attrition. BHOC relevance is presented as a research and system-resilience question, not as a clinical efficacy claim.