The CGM Survey – a preview: Time in range and Psychological benefits

Now that the survey to try and find out what CGM and Libre users thought of the technology and how it had affected their self-management, it’s time to provide a preview of some of the data. I am still processing much of it, however here is the brief preview of the results. Before you start reading, bear in mind that this is a set of data obtained from internet users that have responded to an online survey. It is self reported data, and as such does not have any level of randomisation or strict controls in place to ensure that cross referencing is taking place.

Getting back to the point, the two key takeaway points from this early preview are:

  • Users of CGM systems are more aware of their time in range than prior to using such a system and overall see noticeable improvements.
  • The most cited benefit of continually using these systems is they allow users to worry less about diabetes.

During the life of the survey, 551 people provided their opinions. Of these, 95% were regarding type 1 or LADA users, and around 40% were from outside the UK. 44% used the Abbott Freestyle Libre and 42% used some form of Dexcom. Medtronic showed very poorly compared to these. This is also likely to reflect the UK focus of the survey, where Libre is widely available.

There is still some work to do to look at the age ranges of those for whom these systems are being applied.

51% of users spend more than £1000 per year using CGM-type technologies, whilst 9% of respondees had their CGM paid for by the NHS, and equally, 9% by insurance, so while we know that these are not cheap systems to run, users find that they are worthwhile.

In numerical terms, the benefits of the systems are usually abundantly clear to users, and while I still have to process the changes in Hba1C results, the overall Time-in-Range statistics are interesting to say the least.

Prior to using a continuous recording system, the largest proportion of users had no idea about their time in range. Overall, 45% of the users that responded to the survey didn’t know what their time in range was prior to having a CGM-like system. In addition, of the remainder, about half spent less than half their time in range.

Once CGM had been introduced, overall, the key thing that comes out is that the number of people that didn’t know their time in range dropped from 45% of respondents to 16%, and that 38% now were able to see their time in range as being between 60% and 80%. Before getting the CGM-like system, 10% reported that they spent between 60% and 80% of their time in range.

Perhaps the most interesting change was that before using one of these systems, a time in range of more than 50% was known about by only 22% of the responders. After getting them, this went up to 69%. I suspect that there was an increase in overall proportion of those with their time in range in line with this.

Of those completing the survey, 48% had used the device for 0-1 years, 46% for 1-5 years and 6% for more than five years. Further investigation of this data will reveal which of these are CGM and which are Libre, and should be quite revealing.

83% reported that they still used their device full time, with 11% reporting that they only used it “Sometimes”. Many people took the opportunity to mention that the devices cost too much, with many who still used it complaining about this, as well as those who had stopped as a result of the cost.

Possibly the most interesting set of data comes from the final question of the survey, looking at how these devices change people’s experience of living with Diabetes. A resounding 62% felt that they allowed the user to worry less about their diabetes. This is not a clinical outcome, but a psychological one.

Clearly, the points at 2,3,4 and 5 will have a direct reflection on clinical outcomes, but for a significant number of the responders, peace of mind is of great importance, and these devices have helped with that.

There remains a great deal more analysis to be done on the data, and a report will be provided in due course, not least looking at the age of the user, the changes in Hba1C that the responders have attributed to using these systems, the number of fingerpricks now undertaken, and also breaking down many of the responses to provide further insight into links between aspects of the data. In addition, there is significant analysis of the free-form responses required.

For now though, from a preliminary perspective, the two key takeaways are that by using CGM-like systems, people become much more aware of their time in range and that these systems provide a psychological benefit to a large number of users. This is still useful information!


  1. Thank you for conducting this survey as well as providing the narrative. May I suggest that to fully understand the landscape of cgm user experiences, it is very important to understand ‘how’ a person uses cgm. For example, a similar survey conducted by me a year ago indicated that roughly half of people w cgm are simply using it as a more convenient alternative to a finger prick bgm check. Rate of change and direction were not really utilised by many people which is of course very different than how someone might maximize the benefits offered by cgm. I’m not exactly sure how we categorize or describe the various methods of how one uses cgm but to me that is a critical element of understanding. [co-author Sugar Surfing]

    • I’d agree Kevin, although this is the preview of the easily parsed data. There is also a set of freeform text that I have yet to fully delve into detailing a whole bunch of additional things that people do with CGM. I think that’s where there is some important detail that does not come out in the quick view.

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