Question

One blood glucose meter "a" consistently reads in the high end of the reference range when running the controls. Another meter "b" reads slightly above and below the mean value of the reference range. Which one is more precise? Which one is more accurate? How is accuracy different from precision?

Answer 1

Answer:

Accuracy is the measurement closest to it's actual value and precision is the measurement closest to the other values

Explanation:

A blood glucose machine is important for persons that need to monitor their blood glucose levels as a part of their treatment for insulin related treatment. This machine must be able to give information to the user on the status of their blood glucose level that will allow them to determine their next course of action.

When it comes to accuracy and precision there are things that must be considered. First is that accuracy and precision are independent of each other. Accuracy will require a known or standardized value and the value being measured will have high or low accuracy if the obtained value is closer or further away, respectively. Next, precision depends on how close the two or more values are to each other not necessarily to a standard. For example if one checks their blood sugar reading and it is 200mg/dL three consecutive times in a row this is precise since all the values are close to each other. On the other hand if one checks their blood sugar level once and it is 140 mg/dL this is accurate since it is close to a standard of "normal".

Finally, accuracy and precision are independent of each other but it is important for measurements to be both accurate and precise.