German Scientists Question Accuracy of Prominent Blood Glucose Meters

A recent letter to Diabetes Care called into question the accuracy of blood glucose monitors in measuring low blood sugar.

Nancy Crotti

A letter to Diabetes Care by four German researchers cited a study that tested the accuracy of Bayer's Contour Next blood glucose monitor; Roche Diagnostics' Accu-Chek Aviva Nano; Abbott Diabetes Care. Inc.'s FreeStyle Lite; Nipro Diagnostics, Inc.'s Truetrack; and Johnson & Johnson's One Touch Ultra 2 and One Touch Verio Pro.

The study compared the devices across a range of clinically occurring blood glucose levels. It found that Bayer's Contour Next device performed best at accurately detecting low blood glucose levels. (Bayer plans to sell its diabetes care business to Panasonic.)

The letter's authors--Lutz Heinemann, Eric Zijlstra, Stefan Pleus, and Guido Freckmann--questioned not only the safety of patients using the blood glucose monitors, but also the accuracy of blood glucose monitors during clinical trials.

"Subject safety should be a major concern regarding the possible negative effects of recurring or prolonged hypoglycemia," the letter says. "We wonder whether, from a clinical point of view, greater interest should be displayed in the performance of BGMs in the low glycemic range. This could also help in the documentation of benefits of novel drugs with respect to reduction in hypoglycemia risk."

The challenges of designing blood glucose meters for the mass market are many and varied, according to Bill Evans, president and founder of San Francisco-based Bridge Design, a medical product development company with consumer and professional healthcare clients.

People with diabetes may range from young children to the elderly, and may have Type 1 or Type 2 diabetes. Their monitors measure blood glucose levels, but will vary in how the meter takes into account the patient's level of activity at the time of the reading, or how many carbohydrates the patient ingested, Evans said.

Other design challenges include the willingness of patients to use smartphone apps to both manage their own diabetes as well as to convey their monitor readings to health care providers. Interface designers have to work hard to help make this data useful to many different stakeholders. Because diabetes affects patients worldwide, developers of blood glucose meters must take into account not only varying languages but also different treatment customs and practices used in different countries, he added.

If the monitors are designed to help patients dose insulin, interface designers must design very carefully, to ensure patient safety.

"You layer all these factors onto the average blood glucose meter, which is made in high volume, and that's really quite a challenge," Evans concluded.

Blood glucose device makers compete to become Medicare contract suppliers, which can make their less lucrative and potentially less attractive to spending research dollars. Abbott announced in 2013 that it was focusing on its R&D pipeline to counteract the effect competitive bidding for Medicare patients is having on sales of diabetes devices. 

Blood glucose monitors and accessories, including one monitor included in the study, have previously been the subject of recalls. Johnson & Johnson initiated a voluntary recall of almost two million its OneTouch Verio IQ blood glucose meters in 2013 because the meters might shut off at very high blood glucose readings.

In April 2014, Abbott recalled FreeStyle and FreeStyle Light test strips after FDA said they might provide inaccurate readings of blood glucose when used with the FreeStyle and FreeStyle Flash meters and the Insulet OmniPod. FDA had given the recall Class I status.

A software glitch in Abbott's FreeStyle InsuLinx Blood Glucose Meters distributed between April 18, 2012 and April 1, 2013 was demonstrated to possibly display inaccurate results for patients with extremely high blood glucose levels.

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