“ The accuracy of blood glucose monitoring systems (BGMS) plays a critical role in the management of diabetes,” explains James Richardson, MPharm, MBA. “However, despite rigorous standards for accuracy assessment, previous studies have determined that device accuracy varies widely. To better understand this, our research aimed to evaluate the accuracy of four BGMS currently on the market.”

For a study published in the Journal of Diabetes Science and Technology, Richardson and colleagues conceived of five hypothetical patient scenarios based on low, normal, and high blood glucose levels. “The study was a collaboration between the Institute for Diabetes Technology in Germany and Ascensia Diabetes Care in Switzerland,” Richardson says. “Using information from a recent BGMS study, the researchers devised a method for calculating the anticipated range of blood glucose readings from four BGMS devices. We proposed a methodology that can be used to assess glucose device accuracy and present those results in a clear and meaningful way to healthcare professionals and patients.”

Marketing Authorization Does Not Guarantee Accuracy of the Device

Richardson and colleagues found that despite individual BGMS earning relevant marketing authorization—indicating they have met the necessary performance criteria—it does not guarantee accuracy. “This authorization does not ensure that the device will be accurate enough to prevent adverse clinical outcomes, due to patients making what they believe to be appropriate decisions based on incorrect numbers,” Richardson points out. “Previous studies have shown considerable differences in performance accuracy in the low blood glucose range. However, our study also indicates that differences in accuracy exist among the entire blood glucose range across BGMS currently on the market.”

Based on the true blood glucose values chosen, he adds, it’s evident that some BGMSs are expected to produce results that are in the low- and moderate-risk spectrum. “Using the limits of the glucose expectation ranges, therefore representing worst-case assumptions, it was apparent how different BGMS readings can influence clinical decision making and increase the likelihood of adverse events (Table),” Richardson adds.

Methodology Can Help HCPs and Patients in Device Selection

Healthcare providers who treat people with diabetes require accurate information to make the most appropriate treatment decisions, Richardson says. “Based on our study, knowing that a BGMS meets the acceptance criteria for regulators is not enough to prevent adverse clinical outcomes. Therefore, to create awareness of this issue, our study team proposed a methodology that can be used to translate the accuracy of devices at specific turning points along the blood glucose range into an easy-to-understand and clinically meaningful context.”

In the future, Richardson continues, this methodology could be used in specific product studies to further guide both healthcare professionals and patients in device selection. “Larger datasets, as found in FDA compliant studies, should also be considered,” he says. “This may provide an opportunity to have a higher confidence level than 90% or an even tighter selection of results at a specific blood glucose range. Furthermore, demonstrating accuracy at key turning points of blood glucose levels could be incorporated into future iterations of the relevant regulatory requirements.”

Additionally, says Richardson, a similar methodology could be used to assess the accuracy of continuous glucose monitoring systems and associated decisions in different glucose ranges, particularly when glucose is low. “In light of current and upcoming technologies, it is crucial to use the most accurate devices to obtain the correct information to inform decisions and reduce the chances of experiencing negative clinical outcomes,” he concludes.