There are at least four possible negative consequences of using no-code meters: they might be less accurate, harder to use, more expensive, or lack features some patients want. In this and the July issue, several papers described the accuracy of the no-code meters. Consensus error grids14
showed values in the A zone 98.8% of the time for the FreeStyle Lite, 98.4% of the time for the OneTouch Vita, and 99% for the Ascensia Contour. In other studies, the AgaMatrix Jazz showed A zone 99.4% of the time.9,15–17
All of these systems have passed the International Standards Organization (ISO) 15197 standard used by the European Union to evaluate meters.18
Thus, all of the no-code systems used to present data are acceptably accurate. In my opinion, the best method of evaluating clinical accuracy is the extended ISO 15197 system, in which the percentages of values with less than 5, 10, and 15% inaccuracy (and their appropriate absolute values below 75 mg/dl) are reported. Only the Jazz reports these values now and has an amazing 68% of the values with a less than 5% error.
Roche has presented data that alteration in coding makes little difference to the accuracy of the Aviva BGM monitoring system. As a result, this meter system may be similar to a no-code system.10
The systems are generally not harder to use. Most systems are of average size and weight and are actually easier to use because of the no-code feature.
Price and features are individual items. For the most part, the no-code meters are priced comparably with the brand name meters requiring coding and have similar features.
In summary, the need to code is bothersome for most patients and causes accuracy problems for some. This inaccuracy has the potential to cause poorer blood glucose control and to increase hypoglycemia. Data suggest that no-code meters generally have advantages over meters that require coding. They have similar accuracy, design, features, and price. Each new no-code meter, however, will need to prove its accuracy in independent trials.