External quality assessment scheme for blood coagulation.

ABSTRACT

The aim of setting an External Quality Assessment Scheme (EQAS) for Blood Coagulation is to achieve a harmonization among the participating laboratories on blood coagulation testing. In Indonesia EQAS for blood coagulation is organized by the Department of Clinical Pathology, Faculty of Medicine, University of Indonesia which cooperates with the Indonesian Society of Clinical Pathologists, Jakarta Chapter. Currently coagulation tests in Indonesia are only performed in a limited number of laboratories especially in the hospital. Therefore only 65 laboratories participated in the first trial of EQAS. The control material for EQAS was provided by Organon Teknika and parameters involved in the first trial were PT, INR, APTT, and fibrinogen. Currently there are 7 brands of reagents for coagulation tests available in the market, i.e. Behring, Biomerieux, Biopool, Human, Nycomed, Organon, and Ortho. In the evaluation, the results of each participant were compared to the median of participants who used the same reagent. If the number of participants using a given reagent was less than 10, then the result of each participant was compared to the median of overall participants. The result of a given parameter was classified as within consensus if it fell into the range of median +/- 15%. In the overall evaluation, the percentage of participants which was classified as within consensus for PT, INR, APTT, and fibrinogen were 68%, 64%, 63%, and 67%, respectively, but the CV for PT, INR, APTT, and fibrinogen were 19.84%, 17.89%, 20.21%, and 23.96% respectively. In the evaluation of participating laboratories using Behring's reagent, the percentages of participants classified as within consensus for PT, INR, APTT, and fibrinogen were 72%, 82%, 54%, and 74%, respectively. For Organon's product users, the percentages of those parameters were 84.6%-90%, 48%-75%, 86%, and 67%, respectively. It is concluded that around two-thirds of overall participating laboratories achieved harmonization in the results of coagulation test, but the variation of all parameters is still wide.