Pros & Cons of the Tandem t:slim with Control IQ
Tandem t:slim with Control IQ: “Smahtah” than the average pump
By Gary Scheiner MS, CDCES
I’m a big fan of the new smart car (also pronounced “Smaht Cah”) technologies. What’s not to like? It’s like having another set of eyes watching the road so that you don’t veer into the wrong lane or bump into the car in front of you. You still have to be an attentive driver, but as long as you can put up with a few extra beeps, the “smaht” features make driving a whole lot safer.
Today, we’re in the midst of a smaht technology revolution in diabetes management. Better known as “Hybrid Closed Loop Systems,” or HCLs, they combine an insulin pump, a continuous glucose sensor, and a computer algorithm that adjusts certain aspects of the pump’s insulin delivery automatically. The result is better overall glucose control (particularly more time spent within one’s target range) and less burden on the user to make all the adjustments on their own.
Until recently, we had two HCL options:
- Medtronic’s 670G and a few build-it-yourself system – Loop, Open APS and Android APS. Medtronic’s system can produce pretty decent glucose control, but it comes with a slew of challenges for the user (see review here: https://integrateddiabetes.com/670g-and-me-insights-and-incites-on-medtronics-latest-system/).
- The do-it-yourself systems can produce superior control, but they can be a bear to set up and maintain (see review here: https://integrateddiabetes.com/loop-vs-medtronic-670g/)
Now, we have something new and, some may say, even smahtah: the Tandem t:slim pump with Control IQ technology.
Taking a look at the Tandem t:slim
Tandem’s HCL system features the sleek Tandem t:slim tubed insulin pump with a full-color touch-screen display. CGM data reaches the pump via Bluetooth signals from the Dexcom G6 sensor, which lasts up to 10 days and requires no calibrations. Activating the Control IQ algorithm requires the mere flip of a switch and entry of the user’s weight and average daily insulin requirements. The algorithm predicts where the glucose will be in 30 minutes (based on CGM values and trends) and adjusts the pump’s usual basal delivery based on the predicted value. The system can also administer conservative correction boluses on an hourly basis if the glucose is predicted to be quite high or remains high. It has a preset target of 110 mg/dl.
Extended boluses (but not temporary basal rates) remain an option when Control IQ is running. But the fact is, temp basals are not usually needed since the algorithm makes basal adjustments for the user. If the user knows that their insulin needs will be significantly higher or lower for a certain period of time, they can easily switch to a different “personal profile,” which includes both basal and bolus settings. The system has two optional overrides: An exercise setting (which makes the basal-adjustment algorithm more conservative) and a sleep setting (which makes the basal-adjustment algorithm slightly more aggressive but turns off automated correction boluses).
In pre-market clinical trials, Control IQ achieved glucose management outcomes similar to those of Medtronic in terms of average (mid-100s) and time-in-range (above 70%) with a low frequency of hypoglycemia. However, Tandem’s studies had few restrictions in terms of participation. Our experience (with patients who are well-educated on diabetes self-management) has been that Control IQ produces even better outcomes. Compared to Medtronic, the amount of work required by the user to maintain the system is much, much less. Compared to DIY systems, the setup is much, much easier.
The Tandem pump (along with CGM data) has its own download software (t:connect) which displays sensor and pump data on the same reports, but is a bit clunky to navigate. The reports are clear and simple, but little is offered in the way of computer-generated analysis/insight. The pump can also be downloaded to “midware” programs such as Glooko and Tidepool.
Overall, Tandem’s system offers a nice value proposition for users. It is accessible, easy to set up and use, and produces nice results without adding any extra work/burden for the vast majority of users.
For a side-by-side comparison of all available HCL systems (including a cool star-rating for various features), visit the resources section of our website: https://integrateddiabetes.com/what-is-a-hybrid-closed-loop-system/hybrid-closed-loop-comparisons-options/
Trying to get someone in customer service (technical support) is terrible. Every time I have called the wait time has been hours, that is unacceptable on any scale of measurement. Once you speak to a technical support person they are very helpful, but the response time is problematic . When I was using a Medtronic’s pump the technical support was much better and significantly faster. This company needs to focus more on technical support and less on sells! I would not recommend this pump to a new user for no other reason than the customer service/ technical support is lousy .
Wait times are definitely the bane of diabetes tech! We all suffer with it, and it always seems like companies rotate who is worst at it. If you have an issue that does not require immediate assistance I recommend going to their site
and filling out their message form, someone will email or give you a call back on the issue
Nothing but problems with the Tandem pump and no help. Tubing is deficient, leaks all around the site insertion. Pump will alarm if blood sugar falls too low, but doesn’t stop alarming for a long time even after correction. I was told it uses a AA battery, but pump is charged by an USB plug and takes forever to charge up. I wanted to like this pump but it is defective and Tandem offered no help. Diabetic nurse knew very little about it and had to call a diabetic nurse from Tandem to instruct me. Terrible experience with this pump, no help whatsoever. Tandem will just take your money and run.
Hey S.L. Rough experience there. Our team could work with you to help you find a site and set to reduce issues and walk you through real world use of your pump to make your life with your Tandem more livable.
I was a Medtronic user for 12 years and my last unit was out of date? I went with the Tandem IQ and initially pleased with it, but after using for a few months I found my pump waking me up at night with the warning of high glucose of 200 +. I acknowledged the warning and did a correction bolus if needed. When my level went down to 200, it again woke me up with the same warning message! I acknowledged it again and went back to sleep. This warning is keeping me from sleeping almost every night! I contacted Tandem support team and learned there is nothing I can do about it? It is defaulted to that 200 number? My complaint was submitted to the main office for review? That was at least a month ago. Now my complaint is that when you run out of insulin a loud audible alarm gets your attention and requires you to acknowledge it to turn it off. I’m okay with one warning, but if you don’t stop what you are doing and ad insulin, this pump will keep warning you every 3 minutes! I was driving at the time and it was dangerous trying to remove my pump and reset it! Unfortunately, I had no insulin on me at that time and thought I could get home before running out? So for the next hour, I had to reset my pump every 3 minutes for about 100 miles! Yes I know how to turn my pump off? But I didn’t pack my USB power cable, therefore I could not turn it off! I was ready to throw it out the window and go back to shots! Called Tech suppoprt and was told it is set up that way and nothing can be done about! Again my complaint would go in for review! I’m making everybody aware of this problem in the event you drive for a living and don’t mind loosing sleep every night! Please comment if you have the same complaint, as I don’t know if any else does?
we can’t stop the over 200 alert when in control IQ
First, your settings might need some adjustment if you’re above 200 even after correction
second you can turn control IQ off, I set that alert to vibrate since I can sleep through those.
As for the alarm, nope no way to silence that.
now best practice is to not run out (which I do too on occasion) and of course fill the pump because your DKA risk is now on a tight time clock
but user to user, if you start the load process that beeping stops. You can then go back and finish the process whenever you want and it won’t keep beeping at you, but you’re now taking your DKA risk into your own hands so be careful!
I don’t know if this will work to silence the Empty Pump Alarm on the T-Slim X2, but it worked with my T:Flex. Go to the Load menu and select Change Cartridge. As soon as you see the screen show “Preparing for New Cartridge,” hit the button on the top of the pump. Viola! Your pump shuts up.
I am a retired clinical Dietitian with almost 50 years of type one . I have been a Medtronic user for years and still think the 630 was a fairly good improvement but the 670 was a failure from the get go..
I like tight control and had dawn phenomena which of course Medtronics does not address well. I have now been on the Tandem I Q FOR two month amazing pump. It is as aggressive as the 670 wasn’t.
When my endo told me the new Medtronic pump was using the same algorithm and sensor as 670 that made up my mind to switch. Agree with clip being useless but you can purchase other clips online and the set change out is hmmm a little primitive. So no constant alarms , sleep mode is outstanding no dawn phenomena if you do go high it brings you down a hell of a lot quicker than 670 and I love no 10 times a day finger sticks. Love the dexcom 6
I really appreciated this write-up! Thank you Gary! I am one of “casualties” of being on Medtronic’s 670G for the past 4 years. I got SO burned-out. It improved as they improved the sensors, but readings were still a good 30-40 points off which is a bad place to make ANY treatment decisions regardless of how good the algorhythm seemed. Furthermore, I was also being overdosed on insulin and gained weight on it. Have you heard of others experiencing that? After getting the Dexcom G6, I have finally begun to feel as if I actually know what I am doing again! (Type 1 for 43 years). How much of a challenge was it to switch from the 670G to the Control IQ? I’m nervous about changing pump companies after being with Medtronic all of these years. Do you anticipate that some of the cons you listed may be remedied by Tandem when they update their software? What is this interesting method of filling up cartridges? I think I am a bit spoiled with the Medtronic pumps regarding set changes.
I switched form Medtronic to Tandem, it was no different from any other pump order I’d done really, the biggest difference being that now my supplies don’t come direct from the company (Tandem) they come through a third party distributor, this can be a minor hassle but if you keep on top of your supplies it’s not much different.
The Tandem system works based on our programmed settings, rather than the system’s mysterious calculations, so we are able to tailor in its functioning a LOT more to avoid lows and the excess insulin and weight gain that often comes with hcl start.
The cartridge refill is the one big down side to the Tandem pump. I recommend paying close attention in training, and watching the online tutorial videos to make sure you’re doing it right to avoid having air in your tubing and the accompanying problems there.
No word from Tandem just yet on further software upgrades to control IQ, but Tandem has a decent track record at listening to what customers want and delivering (Certainly more than the other manufacturers) so I’d expect to see some improvements.
Switching form the 670 system to control IQ will proabbly require some retooling of your settings since they tend to get a bit artificially out of whack trying to make Automode (670G) to work well. But we specialize in that area so feel free to give a call and schedule a consult.
I wish the LIES of a “non-stick” Dexcom G6 CGM would stop. I like my Dexcom G6 (overall), but I have to do a finger stick about 30 minutes after a sensor change warmup, because in most cases, I have to calibrate. When I do calibrate, I do another finger stick the next day for a follow up. In most cases I am OK, but from time to time, I have to calibrate again. If I do, I repeat daily, until I am OK. Two finger sticks in ten days is the norm.
Since Jan. 2020, I have had two bad sensors, which initially throws my readings off and would affect the Control-IQ. (No problem in getting the sensors replaced.) With two other different sensors, I have had to make additional calibrations later into the ten days – not the norm, but follow your body ‘s feelings. Ninety eight percent of the time, the Dexcom G6 is almost exact as my glucose meter and clinic lab, but again, watch for the exception.
For a short time now, I am using Basal-IQ (working good) and am looking forward to the Control-IQ, with a close eye on the G6. The Control-IQ will be only as good as the G6 input.
Hi marvin, the “no finger stick” advertising is right up there with “one size fits all” and “individual results may vary” because no two people are going ot have the same experience. many people can use the G6 effectively with only a few finger sticks in a month, others find they need more oversight. We work with our clients to help reduce issues that can lead to reduced accuracy with CGMs as well.
Great post. Wanted to let you know that we hacked my daughter’s clip and it works great. We took an old clip (best clip ever) from J&J Animas Ping, removed the screw to make it smooth, and used 30lbs gorilla double sided tape to attach it to the back of the pump. It’s excellent and has never fallen off!
We love the system, but another con is that exercise mode doesn’t have a schedule, it’s either on or off. And kids forget to turn it off.
PS – email me if you want to see a pic of the hacked clip. Can’t stress enough how great it works.
I am late in the game …my dr is having me look into switching from Medtronic to TSlim
Please show a pic of the clip. i am a very active person …love to exercise and need to have a clip that works for me! Thank you AB
I just found this company that makes some really tough pump holsters
Very good write up on the Tandem, including MOST of the short comings of the pump, by Gary, but your suggestion (Alicia) as to where to buy a better “holder” for the Tpump falls seriously short of the duty of a moderator when you post a link to a site that charges $50 for a case, when Amazon can get you an adequate one for $10 (https://www.amazon.com/s?k=velcro+phone+case+belt+holster&crid=2MXG7YBTDEOTL&sprefix=phone+velcro+holster%2Caps%2C262&ref=nb_sb_ss_ts-doa-p_2_20) that will last years, makes one wonder…Why?
because product options change over time, as do preferences. thanks for the product share.
Thanks for this write-up Gary. Very informative. My t:slim G4 pump just went out of warranty, so I am leaning heavily towards the X2. But I like to read the real-world experiences before diving in.