PB0109 - Consistency evaluation and interference analysis of POCT coagulation test system and fully automatic coagulation analyzing system

Background: Traditional coagulation test in core labs are time-consuming for both registration and blood handling. With the widespread use of POCT service, the tests of PT/INR, TT, and APTT are fast, accurate, portable, and simple. However, comparison and monitoring are hard due to the different reference intervals(RIs). Our the research group previously developed a POCT system with the same RIs, here, the performances were evaluated.

Aims: To evaluate the consistency and correlation between POCT and automatic coagulation analyzer, and to evaluate the possible interference of POCT.

Methods: A total of 451 plasma samples after coagulation tests were collected from 2023.07-10. PT, TT and APTT were detected using POCT. Wilcoxon, Spearman, Passing block and Bland Altman analysis were used for correlation, consistency and conformity between POCT and fully automatic coagulation analyzer. Outliers were selected by Bland Altman analysis, and inconsistent results between the 2 systems were selected based on clinical significance. Correlation analysis of HCT, PLT and other interference were analyzed.

Results: The values of the two detection systems of PT, TT and APTT were 0.866, 0.694 and 0.904 respectively; the conformity were 75.8%, 77.6% and 85.8% respectively. Bland Altman analysis found outliers of 8 PT, 8 TT and 9 APTT, among which 6 PT and 5 TT outliers had higher values in POCT than that in the fully automated system, while 6 APTT outliers had lower values in POCT. Low platelet count, low hemoglobin, and jaundice are interfering factors leading to false elevation of PT, TT and APTT. Clinical significance inconsistency screened 26 PT, 25 TT and 13 APTT, indicating pathological conditions, interferences may be reasons for the inconsistency.

Conclusion(s): The POCT system has good correlation, consistency and compliance. However, the interference of HCT, PLT, hemoglobin, jaundice and other possible interference of POCT should be considered before use.