Development of a World Federation of Hemophilia External Quality Assessment Scheme: results of a pilot study

A World Federation of Hemophilia External Quality Assessment Scheme has been established to promote high standards of laboratory performance in haemophilia centres worldwide. Twenty-two International Haemophilia Training Centres (IHTCs) participated in a pilot study designed to assess between-laboratory agreement and to establish target values for the prothrombin time, activated partial thromboplastin time, factor VIII:C, IX:C and von Willebrand factor assays. Although variations in results and clinical interpretations were observed between the centres, median results and assay precision were comparable to that seen in the United Kingdom National External Quality Assessment Scheme. IHTC-generated median results were therefore considered appropriate target values against which to compare the performance of haemophilia centres in developing countries.