Background: Self-monitoring of blood glucose (BG) is an integral part in the therapy of people with diabetes, which is why blood glucose monitoring systems (BGMS) have to fulfill minimum accuracy requirements. However, accuracy is often assessed by trained operators, although such assessments do not necessarily allow for drawing conclusions on accuracy in the hands of lay users.
Methods: The accuracy of 4 different BGMS (Accu-Chek® Active, Accu-Chek® Performa, Contour®Plus, and OneTouch® SelectSimple™) in the hands of lay users and trained study personnel was assessed in this study. Procedures were based on International Organization for Standardization (ISO) 15197:2013, clause 8, requirements. BGMS measurement results were compared against results from a glucose oxidase and a hexokinase laboratory analyzer. Handling errors made by lay users were documented. Accuracy was evaluated applying ISO 15197:2013/EN ISO 15197:2015 criteria (percentage of results within ±15 mg/dL or ±15%), more stringent criteria (10 mg/dL or 10%, and 5 mg/dL or 5%, respectively), and ISO 15197:2003 system accuracy criteria.
Results: The level of accuracy differed among the four BGMS investigated independent from the operator. One system had less than 95% of the values within each of the limits and one system showed marked differences in accuracy when used by trained personnel and by lay users. Common lay user errors were not checking the test strip codes, incorrect application of blood, and not using the blood drop immediately.
Conclusions: BGMS accuracy can differ when used by trained personnel and when used by lay users. It is important that BGMS manufacturers provide systems that are as insensitive to operator errors as technically possible and easy to use.
Keywords: Accuracy; Blood glucose monitoring system; Self-monitoring of blood glucose; User performance evaluation.