first step in
answering the question regarding how much blood
is transfused (gross data) and who is receiving the
blood (description of recipient populations). However,
this in itself is essentially nothing more than
a data gathering exercise and will not change or
influence practice. Addressing the concern as to
why blood is transfused in various clinical situations
is by far the most challenging question. Answering
this question has the potential to impact substantially
on the other two questions and will be the only
way to effectively control blood usage.