Comparing near misses with actual mistransfusion events: a more accurate reflection of transfusion errors

In a retrospective review of transfusion errors in a large teaching hospita l, we found the true incidence of errors to be at least four times the actu al mistransfusion events detected. Seventy-fine per cent: of the errors wer e detected as near misses. The mistransfusions equated to 1/8610 compatibil ity procedures, and 1/27 007 units of blood issued, whereas the number of t rue transfusion errors equates to 1/2153 compatibility procedures and 1/675 2 units of blood issued. The major error-prone activities included patient identification at phlebotomy and the final infusion of the blood product at the bedside. Of the cases, 95.2% were due to non-compliance with existing guidelines. Potential disasters were avoided only by the vigilance of the b lood bank staff and the systems in place to detect errors.