HBA1C meter, how close?

[asante_za]

I started on metformin on 25 November 2008. I hope to go for my first HBA1C test in January. I have just designed a web based system using my BG readings. It calculates the averages with appropriate weights in the last 120 days as shown below. How close will it be to reality?

Month Average Weight Value
12/2008 4.86 0.5 2.43
11/2008 5.31 0.25 1.33
10/2008 8.02 0.15 1.2
09/2008 9.73 0.1 0.97

HBA1C Value for the last 120 days: 5.93

 

[hanadr]

Hope it works out
I'm due HbA1c in January and since I'm testing less and less, because of strip ration, I'm hoping I've dropped back below 6% . I was 6.1% a year ago.
It isn't a straight average though. the most recent BGs have a greater effect.