Validation of point-of-care INR testing against standard laboratory methods in a Malaysian primary healthcare setting

Abstract

Reliable INR monitoring is crucial for patients on warfarin to prevent thrombotic or bleeding events. This study evaluated the accuracy of the Wondfo POCT device compared to standard laboratory methods (Stago STA-R Max3 and ACL TOP 300) in a primary healthcare setting. The goal was to assess whether this point-of-care testing can provide timely and reliable results for better patient management in community-based clinics. In a prospective, cross-sectional study, samples from 74 patients on warfarin and 20 healthy controls were analyzed. Agreement was assessed using Bland-Altman plots, Deming regression, and CLSI POCT14-A criteria. Deming regression demonstrated strong linear correlations across all comparisons (r > 0.92, R² > 0.84). The mean bias for Wondfo (capillary) remained within CLSI POCT14-A agreement limits for all INR ranges when compared with both Stago and ACL TOP 300 platforms (all SE < AE). A very strong correlation was also observed between Wondfo venous and capillary results (r = 0.954, R² = 0.908). The study concludes that the Wondfo POCT device demonstrates acceptable agreement with standard laboratory testing within therapeutic ranges, thereby offering a viable alternative. It is a reliable and practical solution for rapid, decentralized INR monitoring, particularly in outpatient care, and can potentially improve patient management and safety.