Observers (auditors)- not blinded to the test or control areas - will be asked to audit the bedside check at the time of transfusion. This will be done by direct observation. The auditor will take up a position to observe practice and will therefore be obvious to the staff. However the auditor will not participate in the transfusion check, not answer questions, and not reveal observed errors in the check (unless they observe that the wrong blood will be transfused, in which case they should intervene). Observations will be recorded on the data form.