Comparison of optical and mechanical clot detection methods in coagulation analyses

Background: Measurement techniques vary in terms of laboratory capacity and requirement. In our study, we compared mechanical clot detection system in semi-automated coagulation system to photo-optical clot detection system that used in automated coagulation systems. Methods: We analyzed, prothrombin time (PT), activated partial thromboplastin time (APTT) and international normalization ratio (INR) tests with CoA Data 4004 and Sysmex CS-2000i/CS2100i coagulation systems in 56 plasma samples. PT, APTT and INR levels analyzed with regression analyze, and Bland-Altman graphics using SPSS package program. Approving automated coagulation system as reference, we calculated semi-automated performance using with CLIA total allowable error and external quality reports. Results: Correlation analysis results were r= 0.844 for PT, r=0.842 for INR and r=0.737 for APTT. There was no systematic error in Bland-Altman graphics. While there was no difference PT and INR levels (p=0,314&p=0,196), APTT (p=0,003) showed statistical difference between two methods. CoA Data 4004 device gave lower APTT results. Conclusions: Monitoring coagulation tests are more reliable and accurate when the standardized methods used. In our study, we revealed semi-automated device performance was acceptable because of our results were lessen than CLIA total allowable error limits