Neil Turner's Blog

Blogging about technology and randomness since 2002

The blood donation interval study

Screenshot of the Interval Study web site

I’ve recently volunteered to part of the INTERVAL study, which will look into how frequently blood donors can give blood.

At present, the guidelines are very rigid: men can give every twelve weeks and women can give every sixteen weeks. What the interval study aims to do is allow some people to donate more frequently, whilst monitoring samples of blood taken at the donation. The hope is that, in future, regular donors will be able to give blood more often than at present, boosting blood stocks.

The NHS Blood Service is already facing challenges. The recent heatwave in the UK has led to fewer people giving blood and current stocks of O- and B- blood groups are critically low (less than four days’ worth). The UK also has an ageing population with people living longer, and more blood will be needed to support the very young and very old who can’t donate themselves. And despite recent drives to recruit more donors, only around 4% of people give blood.

Some other EU countries already allow people to donate more frequently. In Austria, it’s eight for men and ten for women. However, there may be factors that affect how regularly individual people can donate, which is why samples will be taken at each donation. This may mean that, following the outcomes of the study, some people will be able to donate more frequently than others. What is most interesting about the study is its size: in total, 50,000 regular donors are needed – 25,000 men and 25,000 women.

I’ll admit that it took me until last year to give my first pint of blood, but I’ve donated twice since then, and agreed to be part of the interval study. Of course, with my luck being as it is, I’m in the control group and can therefore still only give blood every twelve weeks. But some men will be selected to give every ten weeks or even every eight weeks. Women will be able to donate every sixteen weeks (the control group), fourteen or twelve weeks.

There are a few caveats with the interval study. Firstly, you will have to, as far as possible, keep to the regular donation cycle that you have been placed onto with minimal variations. Secondly, the study is for two years, so you will need to sustain the regular donations for this period. Finally, the donations you make will need to be at one of the 24 dedicated blood centres in England; thankfully there’s one in Bradford which is within walking distance from work. But my friends in York would have to go to Leeds, for example.

Hopefully the results of the interval study will confirm that it is safe for people to donate more frequently. Until such a time comes when we can safely and efficiently manufacture replacement blood, our hospitals are reliant on a regular supply of blood from donors. Being able to make optimal use of the small minority who do give blood regularly will benefit so many more patients in urgent need of a transfusion.

If you don’t already give blood, you can find more details on

One Comment

  1. Great blog Neil,

    Interesting that the 4% who already give blood are being asked to give more frequently!