Readings can be quite different. Meters can vary a lot. I have used my meter twice and had two numbers that differed by as much as 12 points. If I took the first one and entered it twice I would affect the overall accuracy of the Dexcom from the very start. I would never recommend that practice.
(In reply to Rickst29)
You really made me go digging on this one - 21 CFR 862.1345 et. seq. does indicate FDA will approve glucose meters for home use with an error of +/- 30%.
VASTLY WRONG is the concept we all need to remember and these devices are TOOLS to help us keep our sweetness under control <<Grin - no pun intended>>.
Your three points are well taken. Ranges vary based on too many variables. There are some tools that should not be sold even as veterinary supplies - yes there have been CGMs on diabetic thoroughbred horsed within 15 miles of my home.
I STRONGLY AGREE with your statements about LifeScan products.
Back to the original question - how many pokes and how many strips?
- the Dexcom internal math is expecting two “real” values on start-up. The math expects the variation and the less it sees the more the Dexcom unit likes it.
- every time I bolus insulin with my pump, I do one stick with one poke and enter it in the Dexcom. This helps the Dexcom unit look at the sensor generated current and relate it to an interstitial glucose reading. Remember, the Dexcom unit works like a wet cell battery generating current from sugar and the impregnated sensor wire. The transmitter tells the receiver how much current is being produced every 5 minutes. The receiver does the calculations and displays the user’s sweetness.
Thanks for the academic challenge - I really like doing these.
Jay - BTW, I am an RN and college faculty member who wears a Ping Pump and a Dexcom CGM.
Lets say a margin of error of 30% is what the fda has set. That range of 70-130 is a big difference. 70 is treated as a low in many, or at least watched as a low in most. 130 is treated as a high in some select few and is viewed good by most. I dont have my dexcom, so I dont know what sort of trouble you may run into if you put a range like that into it. Personally I would most likely wash and dry my hands well if I got a range like that.
My CDE also teaches to test twice on 2 different clean fingers. She doesnt say it has to be two different hands, but she does like two different fingers. And the reason behind that is that something could be on one finger that greatly alters the reading, but the likely hood that the exact amount is on both the 2 different fingers is rarer. She also feels that the cgm asks for 2 different readings for a reason–it wants 2 different readings. If it wanted one start up reading, it would only ask for one.
But ultimately it is your own personal decision to do what you want. I nor anyone else can tell you what to or not to do. But we can share tips and advice. I understand where the ones only doing one reading are coming from. Strips are expensive, and maybe those people dont have insurance or a good insurance that covers strips at a decent price. Paying out of pocket you pay up to a dollar a strip, and some copays can get pretty steep, or you pay out of pocket till a deductible is hit. And in this system of things, you need to be very frugal with your money. Its the result of the way this economy is going. I am just thankful enough I have a decent health plan and a very low copay that I can get enough strips and supplies so I can do things how I want to do them and not have to make shortcuts. From my personal experience, on several occasions, a second test can be very wise if you do not agree with the first. So based on my history I think I will do two pokes, two fingers, two strips as long as my current medical financial status remains the same.