Expert meter users.. Help please!

[bennyg70]

I have this meter too and am going to download all the data on it this week to take a look at.

Out of interest (I never was very great at maths 😛 ) what "should" the standard deviation be, if things were ideal. I have no idea if my numbers on that are good or bad....

Also, do you do post meal tests all the time too??

Hi Laura,

I always post meal test. I dont really see it changing in the near future! It dosnt cost me any time just to know where I am, and you know what its like what works for 3 or 4 days on the 5th dosnt always work out!!

Im not a mathematical genius, So I asked the OH who is a maths teacher @ secondary.

"What is Standard deviation? Whats a good SD?"

OH "I should know, but Im not sure"

...Jesus. God help the kids.

My SD's are as follows after a week testing on it.

Overall - 2.2
Pre meal - 1
Post meal 2.3
bedtime 2.2

All I know is that the lower the number the better!! And I kind of veiw it of an average of the varience from the average... Or something like that??

So pre meal my average is 5.1, so I *Think* it would mean 4.1 - 6.1 most of the time??

However Post meal average is 6.5 so again I think it means in a round about way 4.2 - 8.8... there fore a much wider spread?

Please someone correct me if this is not right!!

 

[lauraw1983]

Hi Laura,

I always post meal test. I dont really see it changing in the near future! It dosnt cost me any time just to know where I am, and you know what its like what works for 3 or 4 days on the 5th dosnt always work out!!

Im not a mathematical genius, So I asked the OH who is a maths teacher @ secondary.

"What is Standard deviation? Whats a good SD?"

OH "I should know, but Im not sure"

...Jesus. God help the kids.

My SD's are as follows after a week testing on it.

Overall - 2.2
Pre meal - 1
Post meal 2.3
bedtime 2.2

All I know is that the lower the number the better!! And I kind of veiw it of an average of the varience from the average... Or something like that??

So pre meal my average is 5.1, so I *Think* it would mean 4.1 - 6.1 most of the time??

However Post meal average is 6.5 so again I think it means in a round about way 4.2 - 8.8... there fore a much wider spread?

Please someone correct me if this is not right!!

LOL at your OH!!! Brilliant!

Mine for the last 7 days are.....

Overall 2.6
Pre meal 2.3
Post meal - don't do them
Bedtime 3.3
Other 3.0

I am aware these are probably not great, because I have had meals out (with booze!) and not really been on the ball with things - I was advise to drop my basal a little as I was dipping low at around 6-7pm most evenings, but by doing that my BG seems just a bit too high overall. Can anyone interpret the above for me - good or bad?!?!

I think I need to go and see my DSN.

 

[everydayupsanddowns]

Exactly right Benny

SD is variance from the mean (average) and is expressed in the same units, so it gives you the + and - from the mean than most (something like 90% if memory serves) of your readings come within.

So average BG of 6 with an SD of 2 means that 90% come between 4 and 8. (hah! yeah right... anyway, back in the real world...)

It is also usually said that tight control (ie lots of closely bunched numbers) will be where SD is approximately one third of the mean. The bigger the SD the more 'spread out' your results are. I prefer to see them in the 2s if possible, but just a few wobbly days can see my SD zooming upwards. It can also help to compare different time periods. One week can be easily skewed by a few dodgy highs (and lows), while a month's worth is more robust.

The only criticism I've seen levelled about SD comes when you don't have very many test results to compare. In that SD tends to naturally fall a little the more results you have - but when I actually tested that with some sample Excel sheets I found that after about 10 results it worked just as you would expect it to - so I think that's a bit more of a maths-nerd quibble.

 

[bennyg70]

Mike did a good peice on the review of the metre and the standard deviation of it vs his pump and vs his old records on MDI before the expert. Its a good comparison vs your own results if you can find it, especially as I view him as someone who knows his stuff !

I think my numbers give a bit of a false picture as ive had a good week, and only had it a week, we'll see what they look like once a get 30 days in, and if my SD was what yours are after 30 days worth of results with averages round 6 Id be happy.

And yes she is a doughnut, we'll walk into a shop , she'll pick up two items and watching her trying to add the prices up is lets say... odd.

 

[bennyg70]

Exactly right Benny

SD is variance from the mean (average) and is expressed in the same units, so it gives you the + and - from the mean than most (something like 90% if memory serves) of your readings come within.

So average BG of 6 with an SD of 2 means that 90% come between 4 and 8. (hah! yeah right... anyway, back in the real world...)

It is also usually said that tight control (ie lots of closely bunched numbers) will be where SD is approximately one third of the mean. The bigger the SD the more 'spread out' your results are. I prefer to see them in the 2s if possible, but just a few wobbly days can see my SD zooming upwards. It can also help to compare different time periods. One week can be easily skewed by a few dodgy highs (and lows), while a month's worth is more robust.

The only criticism I've seen levelled about SD comes when you don't have very many test results to compare. In that SD tends to naturally fall a little the more results you have - but when I actually tested that with some sample Excel sheets I found that after about 10 results it worked just as you would expect it to - so I think that's a bit more of a maths-nerd quibble.

So if your aiming for an average of say 6, you would want an SD of 2 ? the rule of on third?

 

[everydayupsanddowns]

LOL at your OH!!! Brilliant!

Mine for the last 7 days are.....

Overall 2.6
Pre meal 2.3
Post meal - don't do them
Bedtime 3.3
Other 3.0

I am aware these are probably not great, because I have had meals out (with booze!) and not really been on the ball with things - I was advise to drop my basal a little as I was dipping low at around 6-7pm most evenings, but by doing that my BG seems just a bit too high overall. Can anyone interpret the above for me - good or bad?!?!

I think I need to go and see my DSN.

What that suggests to me Laura, is that you are doing really well overall, but that evening meals tend to give you the most varied results (in that your bedtime readings are more spread than anything else.

I find exactly the same myself - eve meals tend to be harder to manage tightly as they are my most varied (and interesting) 🙂

 

[everydayupsanddowns]

So if your aiming for an average of say 6, you would want an SD of 2 ? the rule of on third?

Zackly - then you'd (theoretically) be 4-8 pretty much the whole time.

In practice though this is going to be extremely difficult to manage for any length of time, but BG average of 6.5-7 with an SD around 2.5 or lower if possible would be pretty great numbers IMO

 

[lauraw1983]

Thanks guys!

Well I looked at the 30 day results....and wellllll let's just say.....it's not too pretty.

My overall average is 8.7mmol and SD of 3.4, with 185 tests.

I have just been dealing with so much other stuff (and of course christmas is in amongst those figures too!) that I haven't been on the ball as much as I was before.

Grrr, I am going to email my DSN today.

 

[lauraw1983]

What that suggests to me Laura, is that you are doing really well overall, but that evening meals tend to give you the most varied results (in that your bedtime readings are more spread than anything else.

I find exactly the same myself - eve meals tend to be harder to manage tightly as they are my most varied (and interesting) 🙂

That makes sense....because I often (have to) eat my evening meal later, and when I then test at "bedtime" (on the meter) it's often still a 'post meal' reading as still insulin on board and food digesting...it knows to tell me not to bolus anymore and unless I know something is amiss then I listen to what it says about correction advice etc.

Hmmmm....

 

[everydayupsanddowns]

Mike did a good peice on the review of the metre and the standard deviation of it vs his pump and vs his old records on MDI before the expert....

Thanks for your kind words Benny - we must *never* meet otherwise that bubble will be well and truly burst!

I think this might be the post - results bit is about halfway down: Face off: Pump vs MDI

 

[bennyg70]

Thanks for your kind words Benny - we must *never* meet otherwise that bubble will be well and truly burst!

I think this might be the post - results bit is about halfway down: Face off: Pump vs MDI

Or your head !

Laura, take it as a challenge, I do try and make a game out of my diabetes. If I was 8.5 with a 3.x SD this month, then next month Im going to aim for... 8 with a 2.x SD. For me gaining consitency and less varied results is the thing to tackle first up before lowering the average