To protect blood donor health, we must check if their haemoglobin levels are high enough.

In England, the blood service first tests potential donors with a finger-prick (“copper sulphate”) test. If levels seem low, a more accurate (“HemoCue”) test follows, using a venous blood sample. Other countries use different screening methods.

We are studying 31,000 donors to compare these methods. Our goal is to protect future donors and set best practices for NHSBT.

What is being measured ?

This study is comparing the method used by NHSBT with three promising and newer approaches:

• a version of the “HemoCue” test that requires only a blood drop from a finger prick
• a non-invasive light-shining device (“spectrometer”) placed over a finger for about one minute, which avoids taking a blood sample altogether
• a method that involves predicting current haemoglobin levels from venous blood tested at the previous donation visit, using a “gold standard haematology analyser”.

Who’s involved?

The COMPARE study has been organised and funded by the University of Cambridge, National Institute for Health Research and NHS Blood and Transplant.