HA1C and Glucose Management Indicator (formerly estimate A1C)

Hi
Found this study from 2018 that addresses some of the concerns regarding the GMI vs eA1c vs. automated A1c.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6196826/

We are having an issue with the DCA Vantage Lot # 0654 exp 10/31/25. Since we started using that lot our correlation with the lab ( normally perfect) is off- some patients are showing a 20% difference.

Looks like we have had 0654 at a few of our other clinics but not at the clinic voicing concerns. We use the DCA in our main labs as well so we do not do routine POC to lab comparisons. 

I'm so glad someone posted this!!

We have had two practices out of many that show complaints with 0648 cartridge lot number on numerous patients, DCA versus main lab Cobas 8000  I sent in to Siemens for an investigation but know I will not hear back in some time. We verified the instrument is working as expected with scheduled maintenance performed early. Running high QC on the questionable lot showed it was in but at the very top of the range. New lot ordered and is running fine where both levels of QC are at the mean. I currently have two case numbers going.

We have had that lot number as well in a couple clinics. We have had no issues with QC on any lots. Running around the mean as always with no shifts or trends. We're going to do some meter to meter comparisons  - it won't be on the lots I'm hearing about here as we don't have them any longer. We do not keep large shipments in any location due to storage constraints so we go through lots pretty quickly. 

We had 0654 and our primary care providers raised a concern of major differences between the POCT and Lab values that were repeated did not come back.  Some were in a normal/prediabetic range from our reference lab and the POCT had them in the diabetic range.  We worked with our health system lab (they oversee other ambulatory clinics with the same instrumentation) and noticed that even between lots the variation and bias changed.  I had the clinic move to lot 0660 and the correlation is back within <0.5 limits with only a couple slight outliers.

Also yesterday our distributor shared that Siemens had put kits on a regulatory hold and will let them know when they can release the kits.  No further information or explaination is given.  It seems to be a larger issue and we are waiting from our rep to hear what they have found out, hopefully sometime this week.

For DCA Vantage I also have just received lot 0654103 Exp: 10-31-25 and cannot get level 2 of QC to be in range. It is too high. We use Quantimetrix QC with lot 206650A.  I was going to call Quantimetrix today, but now I will call Siemens to see if I can find out anything. 

Hi Robert,
   That lot should not be used. It is giving patient result 1-2 % higher. I pull a pt correlation monthly with the lab- normally it is right on- but since using lot 0654103 it is off by 1-2 % higher. We have stopped using that lot and will need to call all patients back that that lot was used on. I perform a patient yesterday with lot 0654103 and a new lot siemens sent and with the new lot the result was 7.6% and with lot 0654103 8.8%. I sent all my data to siemens. Siemens will not send a replacement lot until they "finish their investigation". Good luck - we are sending everyone to the lab.

We are having the same complaints from some of our providers, that the DCA is not matching the central lab result. We did a study with samples from our central lab and POC staff performing the DCA test and were within the allowed 8%. We have checked all our QC (no failures) and function checks (within specs). This has escalated to medical leadership. We believe that the issue is probably pre-analytical--the sample is so small and the operators probably not as careful about blood on the outside of the capillary as they should be. We are checking to see if we have any of the lots mentioned in the other posts as well, and I'm trying to get in touch with a technical resource at Siemens. It will not be good if Siemens can't address this issue. The devices are an important part of patient care. If anyone else hears from Siemens, hopefully you'll post here, and I'll do the same.

I had another Practice notify me today. This is our third Practice to notify us. We use the 6% peer acceptability from CAP as our allowed resource. In contacting Siemens tech support today, I hear there has been ongoing studies at Siemens and a customer bulletin is to be released today or tomorrow. The support specialist I was working with did not have specifics, only that it will be on a few lot numbers and nothing on recommendations.  We have ceased testing until we have resolution.

Thank you for that update Erika. I called Siemens support today also.  The support specialist I spoke with did not say anything about a customer bulletin or any issues. But he is sending me a box of another lot and qc to try, should arrive Friday he says. 

If anyone gets that customer bulletin, can you please post it here or a link to it. 
Thank you

I got this communication from my Siemens rep.

DCA Notice.pdf

Thanks you so much! to all who have replied regarding Siemens Vantage A1c problems and particularly to Kathleen for sharing the communication.
Y'all are so appreciated for posting!

Thanks Kathleen, as always! I haven't seen this yet and we as a lab are all about to go talk to the Endo group about A1C's. I'm glad I found this first!

Hi all,
Is anyone having issues with the Vantage lots that are not on the notice?