Table 2.

Description of the themes.

Category and subcategory		Exemplary quotes
		Long-term user	Short-term user
Reciprocal determinisma		“They [care team] always know what to do with me, so there was no problem setting goals because they know that I am trying to be active and healthy. and I kept using it (ePRO app) daily because I know they (care team) are watching my data.” [Female, patient 18]	“I just did not know if anyone is looking at my data, there was no communication from you guys [research team] or my nurse or doctor here. There was no feedback for me about my data, so I felt like I am talking to the void when I was putting my information in. I would like to know if I was doing well or not. It would be helpful to talk to others (peers) about our goals, to see who else is doing the same thing as me and how they are feeling.” [Female, patient 16]
Goal efficacy, behavior capability, and outcome expectanciesb
	Subtheme 2a—confidence and skills in goals	“When my dietician first asked what goal I wanted to set, I knew it would be tracking my everyday walk, I knew it would be easy to keep up at because I have been doing this for long time. But ePRO made me more accountable, I wanted that accountability. I liked how the device asked me if I have achieved my goal for that day. Clicking yes to that felt good and I kept doing that.” [Male, patient 7]	“Setting any goal was hard for me because my conditions flare up here and there and throws me off my routine. So I wasn’t sure how well I can keep up with the goals...I sprained my ankle in last winter so then I was off my walking for 5 weeks. Considering all these troubles, I didn’t work on my goals, and the app became redundant because what would I track. When the app asked Did I achieve my goal for the day, I did not want to keep saying no.” [Male, patient 2]
	Subtheme 2b—confidence and skills in technology	“I expected the app to have some direction for me about how I was doing on my goals, it was nice to see what I was accomplishing weekly basis. No complaints about the app, very easy to use...nothing complicated that anyone will have difficulty with...But I have used computer all my life for work so using this phone or any other phone is not a problem.” [Female, patient 3]	“The small fonts or buttons in this phone [ePRO] was trouble...but I thought I will get used to it (the phone) but did not at the end. I was sometimes working on my goals but could not record it on the phone, so I lost interest in the phone...then I forgot about my goals too because I was not tracking it or doing anything about it.” [Male, patient 21]
	Subtheme 2c—outcome expectancies	“The main reason I enrolled-I wanted to stay on track of my goals and feel healthier over time-I thought the app was helpful to keep me on track.” [Male, patient 1]	“When my doctor suggested this app, I did not know what to expect because there is nothing important, I need to work on, in my opinion anyway. My doctor suggested some goals but nothing very important...I could not make a purpose of it (ePRO).” [Male, patient 11]
Use reinforcementc		“I was bedridden so [provider’s name] she was ‘gung-ho’ that I join her walking group for my recovery. And she said, “why don’t you try this new thing we are doing, this will be good for you?”. And She was right, it was nice to have the app because I know every Monday, I will have to say how many times I walked last week, so I tried to go out over weekends...She was there for me throughout, walking alongside me in every walking group.” [Female, patient 6]	“My doctor did not think ePRO was helping me that much, because both of us thought I am doing fine without it, everything [diabetic symptoms] was on track, so we decided maybe I do not need it.” [Male, patient 17]

^aThis domain refers to the dynamic relationship between individual, context, and behavior.

^bThis domain refers to individuals’ confidence and skills in achieving their goals in the electronic Patient-Reported Outcome app and the perceived usefulness of the app.

^cThis domain refers to the internal or external responses that encourage or discourage behavior change.