Dexcom reports vs. Tandem Reports

so…I recently got a tandem tslim pump and the ability to see both Dexcom reports and Tandem reports.

but…why such a huge swing in the results? same time frame (July 8th thru July 21st)…
My Dexcom reports think I’m on my way to a blue ribbon while my Tandem reports don’t even want to give me a participation trophy.

what gives? Is my average glucose 130 or 203?

@AJZimmerman hey Andy,

The tslim report seems to use the data entered at the panel, and not the CGM data. the key thing that I see is the 7.69 tests per day. Meaning to me that those entered data makes up the content of the report

My meter has min max and average and it’s different than my pump report because I don’t enter normal or low blood sugars into my pump. Only highs. Therefore my pump thinks I am always high. (as do some people I work with)

I would guess that tslim has a sensor report but I don’t use it so I can’t be sure. The CGM data will take into account the lows the highs and the integration. Much more accurate depiction of your control.


yeah Andy @AJZimmerman, your reports look like mine. I thought the reason why mine differs like yours is because I use the G5 - Medicare will not yet allow me to upgrade to the G6 and my pump is “too upgraded” to recognize the G5. A long way to say my Tandem reports are fictitious.

This also tells me something about you. It appears that you only use your pump’s wizard at meals and when you need a correction dose - just the way I use my wizard. I’m hoping my Tandem reports will be more useful when I upgrade sensors [to G6] and activate Basal IQ and Control IQ features.

Andy @AJZimmerman, can I assume that your t-Slim x2 has Basal IQ activated and that you are NOT seeing any values other than time-in-use in the “Basal IQ Technology” section of your t-Connect Dashboard page - the second picture you posted?
I recall reading in either the Dexcom or Tandem user manual that it may be because of the protocol you used during activation. If my memory from a year ago is correct, I believe that you must turn off your Dexcom Receiver while connecting to a “remote device” [your t-Slim] to allow all information to flow. After connecting your pump you can then turn your Dexcom Receiver back on. A call to Tandem or Dexcom might clear this up for you - I’d like to know what solution you may find.

LOL…I was trying to avoid calling tech support at Tandem or Dexcom.
Not that I don’t love being put on perma-hold and being transferred back and forth but that’s a hard pass for me!!!
“You need to speak with Tandem about that!..please hold”
“They said what? No No No, you need to speak to Dexcom about that…please hold!”

I’m going to a weekend Type1 retreat/convention middle of next month where reps for both companies will be on site. I’ll ask then…

Thanks for the good info, guys. I’m (thankfully) switching to Tandem in January. Just yesterday, a friend was trying to explain how her Tandem results didn’t match Dexcom. Now I get it!

@mikefarley, this is the explanation from Tandem.

Can I use a separate Dexcom receiver to view my data, in addition to the pump?
No. A single transmitter cannot be connected to both your insulin pump and a Dexcom receiver at the same time. Dexcom CGM transmitters can only be paired with one medical device (either a Dexcom receiver or t:slim X2™ insulin pump) and one consumer device (phone or tablet) at the same time.

Can I still use the Dexcom Share feature with my t:slim X2 pump?
Yes. The Dexcom transmitter can pair with one medical device (either a t:slim X2 or a Dexcom receiver), and one consumer device (phone or tablet) at the same time, allowing you to continue using the Dexcom Share feature as you were before.

There may be a work-around for this available.

@Dennis your response got trapped in my junk mail folder :slightly_smiling_face:. I will have to discuss using Share with my friend. I think she’s under the impression that Dexcom doesn’t work at all with Tandem. I’m currently running Loop, so I use different tools than she. Trying to get a few things sorted out before I move to Tandem in January. Thanks for your response.

@Dennis, I was just rereading the earlier messages in this thread. I had overlooked your comment regarding being on Medicare and using G5. If it’s not a privacy intrusion… are you on a Medicare Advantage Plan? If yes, which one? My current plan doesn’t cover Dexcom at all, even if I get the Tandem pump, so I’m looking for a new plan. So far, my experience is they will not tell me which CGM codes they cover until AFTER I’m a plan member!

Hi @mikefarley, no intrusion at all. I’ve been on AARP Medicare Advantaged serviced by United Health Care.

UHC generally will not cover either Tandem pumps or Dexcom CGM but I am thinking that Medicare overrules. I went directly through both the Dexcom and Tandem representatives to bet complete coverage - they did all the work. For billing purposes my supplies must be ordered through Byram. I understand the chosen supplier may differ by state; but once again both Tandem and Dexcom did the work.

Thanks for the details!