Interference testing: why following standards is not always the right thing to do.

Lucarelli and colleagues in this issue of Journal of Diabetes Science and Technology describe the results of interference testing for a continuous glucose monitoring system. The authors follow the Clinical Laboratory Standards Institute guideline EP7-A2, including their conclusions, in which the concepts of a statistically significant interfering substance and a clinically important interference have been combined in a way whereby information from the experiment has been lost and could be misleading. A better way to treat the data is presented, including a simulation method to evaluate the effects of interferences.