July 7, 2016
Test Strip Accuracy Matters – Part 2
Health authorities, but not the FDA, in the United States and in other countries recognize the importance of accuracy for self-monitoring of blood glucose. The American Association of Clinical Endocrinologists/American College of Endocrinology Clinical Practice Guidelines for Developing a Diabetes Mellitus Comprehensive Care Plan (2015) state that “self-monitoring of blood glucose (SMBG) is an important tactic to help patients document hypoglycemia, although it is essential that the glucose meter meet accuracy standards.”
In 2013, the International Organization for Standardization (ISO) tightened accuracy standards for BGMS to require analytical accuracy be within ±15 mg/dl when glucose concentrations are less than 100 mg/dl, and within ±15% for samples with glucose concentrations greater than or equal to100 mg/dl. According to the FDA’s 2014 draft guidance accuracy standards for BGMS, 95% of results should be within ±15% and 99% of results within ±20% across the entire glycemic range.
Even within the boundaries of these standards, considerable differences exist in the performance of commercially available systems, especially in the low glucose range. Even the Centers for Medicare and Medicaid Services is forcing BGMS of very poor quality on Medicare beneficiaries in an effort to reduce costs, the beneficiaries be damned.
These performance differences can potentially have a major impact on the risk for missing detection of hypoglycemic events and thus adequately identifying and treating them. (See Figure 1.) For example, fewer than 1 in 100 hypoglycemic events will be missed via self-monitoring of blood glucose at 10% error level; at 20% error level, the risk increases more than 10-fold, to 1 in 10 hypoglycemic events missed.
Meters that have only a ±20% level of accuracy are still on the market and in patients’ homes. Help your patients understand that the accuracy of their blood glucose meter matters, more than they might think.