Increased frequency of blood donation is feasible and safe and may help the management of blood stocks during periods of high demand, according to a large UK study.
But concerns have been raised that it could lead to iron deficiency for some people.
The randomised controlled trial of more than 45,000 people compared inter-donation intervals of eight and ten weeks against the usual 12 weeks in men and 12 and 14 weeks against the usual 16 weeks in women.
They found more frequent donation over the two-year study period resulted in substantially more blood collected without having a major effect on donors’ quality of life, physical activity or cognitive function.
However the trial found more frequent donation was associated with more donation-related symptoms such as tiredness, breathlessness, dizziness and restless legs, especially in men.
Deferrals of blood donation due to low haemoglobin also increased as did iron deficiency in both men and women.
One third of men (33%) on the 8-weekly schedule deferred at least one blood donation due to low haemoglobin and a similar proportion of women (31%) on the most frequent donation schedule.
The study authors said deferrals of donations were essential to protect donors, but were also ‘time consuming and costly for blood services and demotivating for donors’.
They suggested frequent donation might be more effective in subgroups of donors such as those with higher than average weight or those with higher than average initial haemoglobin or ferritin concentrations.
A Comment in The Lancet from US researchers said while the UK study was ‘groundbreaking’, it led to iron deficiency in about 25% of the men and women giving blood most often.
“Blood donors already provide the life-saving resource of blood through their altruistic donations and should not be asked to pay the additional price of iron deficiency.”
“Teenage blood donors might be particularly susceptible to the negative consequences of iron deficiency and should be treated with increased care.”
They said blood centres already have the tools to balance supply and demand, monitor donor health, provide iron supplementation and personalise donation intervals.