Table 3.

Example Quotes by Theme and Participant Type

Theme	Participant type	Example quotes
Mental and emotional burden	Adult	…Part of that anxiety was the, you know, ripping my hair out learning how to use the thing, but I didn't enjoy the anxiety, so that, that certainly was part of contributing to what, what caused me to just stop using it. …It's obviously the garbage in, garbage out problem when you're making predictive modeling, that the getting them dead-on matters a lot more, your prediction comes out way off. And then you wind up on the, I would wind up on a roller coaster of my, you know, my glucose soaring up and down, which made it very hard for me to work, because I'd be in a fog all day. And I had a pretty good A1c going in. I had a 6.3, more or less, starting, when we started the study at least, so there'd definitely be an improvement, I know I could get an improvement with it, but the problem was the cost of it was I couldn't, I couldn't concentrate anymore at work. It was just, it was just, really, it felt like fog in my brain.
	Parent	We felt like it was a little more stressful for us to be on it than the advantages of it. There were a lot of technological issues that we were experiencing… So, it was just causing a lot of stress and it was a difficult decision, we felt like it was the best thing to do for him, it was to stop. Yeah, it was just, it was really frustrating. He just ran high a lot. Yeah, my wife and I were frustrated to see those. He actually said, we are doing terrible with this. I want to stop using it.
Adjusting settings	Adult	It did not meet my expectations as far as lessening of the burden of diabetes management. What I found was that there, as everybody says, you just—it's not set it and forget it. You've got to get the settings absolutely right. And those are all of the settings that have to do with the inputs for the algorithm to deal with. So that's insulin-to-carb ratios, insulin sensitivity factor, whatever else. And if the algorithm doesn't have those set just right, it's not going to be able to come up with appropriate dosage. So, getting those settings right entailed like months of constant reading of the document and just getting the whole application written. Well, my issue was for nine months I felt like I was constantly trying to adjust my settings and just could never figure out a good setting and my frustration was I had had such good control for so long that I just felt like my control was getting so much worse because I couldn't get the numbers right. I think if it would have taken less than five months to get my settings dialed in, somebody who had knowledge and was willing to work with me, somebody not just a Mentor but someone with credentials and understanding of the system. I know that there are a lot of people who are knowledgeable including the people who developed and programmed Loop and the Facebook group that exists, but I felt like a real roadblock in reaching out to them in particular because so many people are contacting them and bothering them. Yeah. They are just people like me, but there was nobody who…it was hard to sift through the available mentors between who had experience with people similar to me, there are a lot of parents with kids, there were people who have been on the system for a month who are mentoring people, well, I didn't want that. Umm…it was just hard to identify who would be a good Mentor and who had the same goals.
	Parent	So, for us, kind of the driving factor was her going to school and needing to either get her settings dialed in before we send her off to school or having to put it on hold. So ultimately, we just couldn't get it dialed in where we wanted it to be. It felt like we had better control off of it than on it.
Fear of disapproval	Parent	Well, one of the concerns that I had had when we started was, how our endocrinologist was going to respond, so that was. As that appointment was getting closer, I was getting more nervous about what she would say…I was worried about what the appointment would be like when we would take our devices for the download and there would be nothing to download because we are delivering the insulin through the phone instead of through the PDM, so I just wanted to avoid that conversation.
Specific circumstances or concerns	Adult	For myself personally, I am like afraid to bolus for meals…because I am afraid of lows. I didn't never have any like severe-severe lows, but I would be high and it would be and I will be kicking in an extra basal and then I would just get these double down arrows and then it would show me how it is going to be a negative number and I know that it is not always not accurate but like me and I am taking care of two small kids at home and I said why I cannot be risking having like a severe incidence when I am with my kiddos.