The Effects of Plasma Prothrombine Time and Activated Partial Thromboplastin Time Based on Different Instruments and Methods

Introduction: Many laboratories have more than one coagulometer with different types and methods that are used simultaneously. In patients requiring Plasma Prothrombine Time (PPT) and Activated Partial Thromboplastin Time (APTT), follow-up treatments may be performed on different instruments. Aim: To analyse whether there are differences in the value of PPT and APTT between 3 instruments with different methods. Materials and Methods: This study took 64 samples of patients with End Stage Renal Disease (ESRD) who underwent haemodialysis in Haemodialysis Centre of Dr. Soetomo General Hospital Surabaya between June 2017 and October 2017. All samples were carried out by examination of PPT and APTT on three instruments: CoaDATA 501 with one wavelength optical detection, Sysmex CS2100i with three wavelengths optical detection, and STA Compact using electromechanical methods. Results: Significantly different results were obtained in the PPT comparison between the group of CoaData with Sysmex CS2100i (p <= 0.001) and CoaData with STA Compact (p <= 0.001). While in the intergroup APTT, all gave significantly different test results (p<0.001). Conclusion: Because of difference value of PPT and APTT in difference instrument and method, therefore serial tests should be performed in the same instrument to obtain valid and reliable results.