Certified Diabetes Care and Education Specialist (CDCES) Practice Exam

Which of the following is least likely to account for discrepancies between SMBG results and A1C levels?

1. Checking BG results only prebreakfast and predinner

2. Comparing the 90-day meter average with an A1C

3. Meter inaccuracy

4. Incorrect SMBG technique

The correct answer is: Comparing the 90-day meter average with an A1C

The reasoning behind why comparing the 90-day meter average with an A1C is least likely to account for discrepancies between self-monitoring blood glucose (SMBG) results and A1C levels lies in the nature of what A1C measures versus what SMBG reflects. A1C provides an average blood glucose level over the past two to three months, using a weighted average that considers fluctuations throughout the day and night. On the other hand, SMBG often captures glucose readings at specific times, such as premeal and postmeal, which may not provide a complete picture of a patient's glucose control. When evaluating the 90-day meter average, it is essentially a summary of frequent SMBG readings, which should be consistent with the long-term average that A1C represents. However, discrepancies are primarily influenced by factors like meter accuracy, the timing of blood glucose checks, and potential errors in technique rather than the comparison itself. Thus, the act of comparing the meter average with A1C provides a useful, overall perspective, rather than a source of discrepancy. Other factors like checking blood glucose only at specific times can lead to incomplete data about postprandial spikes, inaccuracies could be due to malfunctioning meters leading to erroneous readings