Concerns about SD Codefree

[Squire Fulwood]

Who's panicking?

 

[catza]

I did.

 

[angieG]

very interesting charts and as supportive of the SD as those that Home Health forwarded on to me some weeks ago but what I would like explained is the following:-

This morning I got a reading from the SD of 5.2 and thinking that I wasn't expecting that since I was just starting to shake I put a test strip into my freedom lite and from the same drop of blood I got a reading of 4.1. That's about a 20% difference according to how you do your sums.

Never mind the charts, should I be concerned about the above.

I have just opened a new pot of freestyle Lite test strips (same Lot and Batch number as the previous pot) and they are reading about 1.0 or more ABOVE the SD Codefree, whereas the last pot was reading about 0.8 below. I had a couple left from the previous Freestyle Lite pot so checked one of those and it read 0.6 lower than the new Freestyle pot one.
On checking these out this morning I got 3 readings varying by about 1.9 with the SD being the lowest all from the same finger at the same time!! :shock:

I have noticed this before with the Freestyle ones but have never done a straight comparison like this before.

Regards
Angie

 

[Squire Fulwood]

Angie. I find that the difference between the two meters varies according to which part of the range you are reading. They can be 20% apart at low readings, 30% or more apart at high readings but only about 10% mid range.

So far in all the tests I have done the SD reads higher so your results do not compare with mine. As I have said elsewhere on this forum, I use the SD and take 10% off the reading. This is not in order to cheat but so that my nurse and I have a similar range of numbers to discuss. It also means £5 for 50 strips, not that I am counting. (Ahem).

 

[angieG]

I agree, and that is what I have been doing.....that is until now!!
My SD has been pretty consistently higher than the Freestyle Lite and I have got the hang of comparable levels when testing with either one.....until I opened this latest pot when I got a higher than expected reading from the Freestyle Lite and compared it.

I am having enough trouble trying to keep my readings to anything bordering normal at the moment without the hassle of variations in test strip batches :thumbdown:

I'll be joining tree-peony on her grass diet soon!!

Angie

 

[Squire Fulwood]

I got the shakes a little worse before lunch today and I took readings. The SD reading was 4.8 and the Freestyle was 3.8. This is not worth panicking over since I am very well aware that the SD reads high. However, I have adjusted my spreadsheet so that when readings are in the lower range they are reduced by 20% instead of the 10% hitherto. The low range now gives the same number from both meters.

 

[jammy1988]

Hi, I was wondering what the consensus seems to be over the accuracy of the SD Codefree? I'm a non-diabetic who has been monitoring my blood glucose due to concerns I have had about my health.

A few months ago my fasting levels were in the mid to low 4s, but since improving my diet and exercise they have actually gone up to the mid 5s. My BG also seems to stay relatively high (for a non-diabetic) during the day, often hovering around 6 or above, and then actually dropping after I have a snack. This all seemed a bit strange to me. I actually had a health assessment today where my BG was taken, producing a result of 4.1. A few minutes later I used my SD meter and got 5.4, leading me to wonder whether the unusual BG trend I've noticed may actually be down to an inaccurate meter. It still seems to produce quite consistent readings, but I'm wondering if they are perhaps rather high.

 

[Squire Fulwood]

The subject of the SD meter comes up repeatedly because it reads higher than other meters. I should point out that none of the meters are accurate and can only be used as indicators for the most part. My only concern about a meter is that when I talk to my nurse we are talking about a similar range of numbers.

As yet there is no detectable consensus that I can see. Some people criticise the SD saying that it reads high and others support it by saying that if it reads within range using artificial blood then it must be ok. Many are pleased that test strips for the SD cost a fraction compared to those of other meters. For people who cannot get free test strips on the NHS this is an important consideration.

I have two meters one of which is an SD and they give different readings. The SD is about 20% higher in the lower ranges (say up to 6), 10% higher in the mid range (say up to 12) and anything up to 30% higher in the higher range.

The only datum point I am aware of is that my nurse says that below 4 and I am in danger of a hypo. My other meter tends to agree with this statement whereas the SD is still reading up to 5. I take the SD reading, take 20% off it so that my nurse and I are on the same range and enjoy the cheaper test strips.

 

[BaliRob]

The 20% adjustment should not be necessary - the Govt should insist that manufacturers co-operate with each other on the manufacture of such an important piece of medical equipment. 20% is disgraceful discrepancy!!!

 

[Squire Fulwood]

The 20% adjustment should not be necessary - the Govt should insist that manufacturers co-operate with each other on the manufacture of such an important piece of medical equipment. 20% is disgraceful discrepancy!!!

It would be nice if we didn't have to worry about discrepancies but they seem to be a fact of life. My other meter is a Freestyle Freedom Lite and according to the research done by the Zurich University that one reads 10% low. They also say that the SD reads 2% low but I don't remember if they give any results covering the range of readings or indeed what level of sugar they tested. They don't show the 20% and 30% that I get.

I tested both meters on the same drop of artificial blood in the high range. The Freestyle read 13 and the SD 20.

The Freestyle is the one that seems to agree more closely to what they expect at my surgery so I try to record readings as if they were all taken by that one.

 

[Squire Fulwood]

 

[jammy1988]

I've had the chance to do a few comparisons between my SD and new Freestyle Lite now. In every case so far the SD has come out higher, always being at least 0.5 above the Freestyle.

Of the tests this morning for example, my fasting was 4.8 with Freestyle, 5.4 with SD.

40 minutes after a breakfast of a fillet of fish, fried onions and cannellini beans with chopped tomatoes (36g protein, 31g carb, 5g fat), the Freestyle gave 6.1, but the SD gave readings of 7.7 and 7.8.

After 1 hour the Freestyle gave 4.8 and the SD 5.4.

Obviously the 1 hour readings are fine either way, but the SD readings at 40 minutes do seem rather high considering the meal I had (relatively few and low GI carbs), and the Freestyle reading seems far more reasonable. My issue is that I have been growing concerned with the raised fasting levels (on the borderline of IPG diagnostic values) and high peaks I've been getting in recent months after meals that shouldn't really cause spikes, and which also seem counter-intuitive considering the vast improvements in my diet (particularly in terms of fewer refined carbs) and exercise in that time. The disparity between the readings seems to be quite consistent at the lower levels, but then seems to grow quite significantly for postprandial readings.

I'm wondering whether the SD might perhaps be affected by some substance in my blood whose levels have changed as a result of my changing diet for example, or whether the meter has for some reason 'drifted' - such that it still provides 'precise' but not 'accurate' readings.

 

[catza]

Could I ask if you have started to use a new batch of strips and what is the batch number of the strips you are currently using ?

I have had the same higher readings with my Codefree since I started using Batch number S0312006. The higher readings were enough to prompt me to contact the UK supplier with my concerns and they requested tests on the accuracy of the Codefree strips from the manufacturer. The results that were then sent to me can be seen in my post on this thread dated 6th June. All the test show that the codefree strips tested were within the prescribed accuracy parameters and that the codefree readings were pretty much middle of the road against other meters but it still doesn't help when each new batch of strips is inconsistent with the previous batch.

I was getting overall readings of mid4/5 with the batch before the one I am using now but this current batch is giving me readings of high5/6/7 which to this very low carber is quite discombobulating. :shock:

My backup meter, a Caresens N, is still recording 4/5 on the odd occasion when I really need to double check an unexpected +2 reading but I can't afford to start buying strips for that meter in the quantities I use day to day.

I do realise I am getting consistent readings with the codefree strips and that they are consistent enough to catch, and allow me to correct, any jumps in my carb intake but I would be happier if I could trust the figures I am getting as my next HbA1c test is still 3 months away.

 

[Squire Fulwood]

I know it wasn't me you asked to provide batch numbers but since I have a number of empty containers I got the following batch numbers from them.

S0312006
S0312004
S0311173

They have all recorded high. You can see from my earlier posts that since I find the price of the test strips attractive I have done many comparisons and multiply my SD readings by a fiddle factor in an attempt to cause them to look like the results from the Freestyle.

 

[catza]

Hi Squire, like you S0312006 is the one I am getting higher readings from but S0311173 was the last batch I had and they were giving lower readings for me and were consistent with the first batch of strips I bought in late February.. I have bought strips 3 times up to now and didn't think to keep a record of the batch number of the first set of strips but comparing our batch numbers with the batches used by the manufacturers of the code free it seems as though the ones they tested were older S0309001SP, S0309002SP S0309003SP than any we have had problems with.

Don't quite know what to do in the future, I have about 2 weeks supply left of 2006 but I think having to double check any unexplained higher readings will do my stress levels no good at all and that will screw up my levels as well. I don't really mind if my meter reads a tad high or low just as long as it is consistent.

I would hate to think what effect these higher/lower results from different batches would have on someone who was struggling with higher levels and getting frustrated with seemingly unexplained reactions to their diet changes. In fact I would now be hesitant to recommend the SD Codefree despite it's competitive prices.

 

[Squire Fulwood]

The SD has been consistent but it has been consistently high compared to other meters according to many of the posts on here. There is not a problem for the most part but the feeling I am getting is that if you tend toward hypos then the SD can be misleading. In the critical range below 4 the SD appears the read above 4 and this is not good for some people.

There is a tale where someone passed out and an SD read 5 and all was well until a medic pointed out that the reading was not helping.

In the high range, if you are getting towards 10 or above then the SD appears to accelerate into the stars.

I don't know which one is right. I am just a T2. Just use your meter for relative readings.

If you go hypo at 5 then that is your number.

 

[angieG]

I have recently bought some strips for my Bayer Contour (I stopped using this as the SD strips are far cheaper) as I ran out of my prescribed Freestyle Lite strips (not due more until tomorrow) so I can now compare the SD and Contour.

Unlike the Freestyle Lite that has been reading slightly lower than my SD, I have double tested a few times with the Contour and some readings have been identical within 0.2, some have had the SD slightly higher and the odd one has seen the Contour reading higher than the SD.

I still believe it is very dependent upon the uptake of the blood by the strip. If there is a slow or stuttering uptake the reading seems to go high. If the blood is applied from slightly under the tip of the strip and it travels quickly in one movement up the line then the reading will be pretty comparable to that of other meters.....well that's how my blood works :lol: but then maybe I'm strange!

HTH
Angie

 

[Squire Fulwood]

I think it's about time that we stopped chasing the Holy Grail of accuracy in a meter and accept the fact that none of them are accurate. The Zurich research more or less confirms this.

Each of us will have to learn to use the meter we have or can afford. I have said in earlier posts that my main concern is communicating with my nurse. If I am talking SD and she is talking Freestyle then there is room for misunderstanding. This is why I lower the readings of my SD in an attempt to look like the Freestyle but get strips at a third of the price.

Strangely the Zurich research has the Freestyle at 10% low and the SD at 2% low. This difference of approaching 10% is more or less what I see in the mid range of readings. I see much worse differences in other parts of the scale.

I have learned the wrinkles of the SD and am now confident using it so I shall enjoy paying about 5.99 for the strips.

 

[angieG]

Squire,
I totally agree.
When you can get 250 strips for the price of 50 regular ones there has got to be a bit of variation in quality else someone is making a fortune out the others!
Let's enjoy the cheap ones while they last.
Regards
Angie

 

[jammy1988]

I had a fasting BG test done recently so I decided to use this opportunity to do a very unscientific test of the SD. The lab result came back with 4.3, but my SD reading (taken just after the blood sample was taken) was 5.2, with the Freestyle reading 4.5. As I said, not exactly the most rigorous of tests, but it does add to my suspicions that the SD readings have been unusually elevated for a while.

Incidentally, I also had a HbA1c test, which came back at 32. I think it was 33 when I had it done a few months ago around the time I made significant changes to my diet and exercise, so not much change there.

Anyway, it has at least put my mind at rest a bit.