Abstract
Objective: To assess the analytical performance of Accu check Active®, One Touch Ultra®, On Call Plus® and Nova Stat Strip® glucose monitoring point of care devices, when compared to each other and with Roche ® Hexokinase method on Hitachi 902 ® automated chemistry analyzer in the presence of interferants like hematocrits and ascorbic acid.
Methodology: The study was conducted at Dr. Ziauddin Hospital, Karachi from May 2014 to September 2014. Venous blood samples were modified pre-analytically to generate varying hematocrits. Samples were glycolyzed or spiked to achieve various glucose levels. Similarly, different levels of ascorbic acid were also added and glucose tested on blood glucose monitoring devices and automated chemistry analyzer. This process generated 18 different combinations of glucose with hematocrit or ascorbic acid.
Results: Differences in hematocrit and ascorbic acid levels brought about significant changes in glucose measurements in the glucometers. The Nova Stat Strip® displayed results close to the analyzer in the presence of interfering substances. The Accucheck Active® and One Touch Ultra® had a similar performance, while the On Call Plus® showed the most variability of results.
ISO 15197:2013 requirements were fulfilled by Nova Stat Strip® and Accucheck Active® while the One Touch Ultra® and On Call Plus® did not reach the acceptable limits.
Conclusion: Hospitalized patients have a multitude of interfering substances in their blood, which bring about a significant difference in glucose readings. Glucose monitoring devices designed with additional strips to minimize interference by interfering agents are more accurate and should be preferred over other devices for use in hospitals point of care testing and self monitoring.

Key words: Glucose, blood glucose self monitoring, point of care systems.