The UK’s National Blood Service screens all donors for a variety of health and lifestyle risks prior donation. Many are highly sensitive, particularly sexual history and drug use. So I found it disappointing that, after consulting with a nurse who took detailed notes about specific behaviours and when they occurred, I was expected to consent to this information being stored indefinitely. When I pressed as to why this data is retained, I was told it was necessary so that I can be contacted as soon as I’m eligible again to donate blood, and to prevent me from donating before that.
The first reason seems weak, as contacting donors on an annual or semi-annual basis wouldn’t greatly decrease the level of donation (most risk-factor restrictions last at least 12 months or are indefinite). The second reason is a security fantasy, as it would only detect donors who lie at a second visit after being honest initially. I doubt donor dishonesty is a major problem and all blood is tested anyway. The purpose of lifestyle restrictions is to reduce the base rate of unsafe blood because all tests have false negatives. Storing detailed donor history doesn’t even have much time-saving benefit: history needs to be re-taken before each donation, since lifestyle risks can change.