Performance evaluation of a new Stago^® automated haemostasis analyser: The STA R Max^® 2

The STA R Max^® 2 is a new coagulation analyser developed by Diagnostica Stago, able to perform clotting, chromogenic and immuno-turbidimetric tests. A pre-analytical module build into the cap-piercing needle performs the sample integrity verification (sample tube filling and measurement of haemolysis, icterus, lipaemia). The STA R Max^® 2 analyser incorporates an accreditation program tools to assist technical validation of the analyser. We assessed the analytical performance of the STA R Max^® 2.

The following tests were assessed: prothrombin time, activated partial thromboplastin time, thrombin time, fibrinogen, factor V (FV), antithrombin (AT), D-dimers (DDI) and von Willebrand factor antigen. The assay precisions were assessed using fresh plasma samples or internal quality controls. An inter-analyser comparison was performed with a STA-R Evolution^® analyser or, for the FV, with a BCS^® XP System. Haemolysis and icterus detection were also verified.

For the intra-assay precision, the coefficients of variation (CV%) were all less than 5% and for DDI, the standard deviation (SD) was less than 0.1. For the inter-assay study, all CV% were less than 5%, with the exception of FV and AT (FV: 6.68% and 5.27%; AT: 7% and 12.14% for normal and pathological values, respectively). SD was less than 0.1 for DDI. The inter-analyser comparison demonstrated good results. Haemolysis and icterus were detected correctly for all our assessed samples.

According to our methods validation's recommendations, the results demonstrated a good technical and analytical performance of the STA R Max^® 2 analysers for the tests assessed.