Method comparison between two hemostasis analyzers: STA R Max3 and Cobas t 511

The STA R Max3 (Stago, France) and Cobas t511 (Roche Diagnostics, Germany) are two automated hemostasis analysers that can be used to perform a wide range of tests. The STA R Max3 uses a mechanical clot detection system to measure coagulation times, while the Cobas t511 uses optical detection. The aim of this study was to compare the analytical performance of these two analysers using fresh plasma samples with or without a risk of interference due to hemolysis or lipemia. For plasma samples without interference, acceptable agreement was observed for prothrombin time (PT) (n = 55), activated partial thromboplastin time (APTT) (n = 56), fibrinogen (n = 56) and factor II (n = 43) with R² of 0.907, 0.963, 0.979 and 0.968 respectively. For factor V (n = 43) and D-dimers (n = 45), agreement was less acceptable, with respective R² of 0.756 and 0.887, but with no clinical impact. For hemolysed samples, acceptable results were observed for PT, fibrinogen and D-dimers, but three results were clinically discordant for APTT, and STA R Max3 offered greater robustness for processing highly lipemic samples.