Doubt with glycemia machines

Hello, I'm new !!!!!!! I am starting to work in AP, and my doubt is how much difference there may be between two glycemia machines, because I have some patient who gives me differences of between 20 and 50, and I think thatIt's too much then what should I do ???, thank you very much Giulia

Use only one machine.There will always be differences.Especially the lower or high this glycemia.The meters are calibrated for "normal" glycemia values, and it is in that range where they are more close.And in addition, its error percentage will always be more pronounced the higher the figure of glycemia, the most spectacular difference being.

I was extended to mine and when I took it to my health center, they compared it to the one they had there, and the nurse told me that there may be a difference of 30. If it is greater it is not well any of the two.