Table 2.

Factors influencing each RE-AIM dimension, as reported by GPs and patients during interviews and focus groups

	Factors reported by
	GPs	Illustrative GP quote	Patients	Illustrative patient quote
RE-AIM dimension
Reach	Limitations of the inclusion criteria	“It’s complex, but I think there were a few interesting patients we could have included, if French and English were included as languages for consultation.” (Quote GP1.1 Focus group 3)
	Varying usefulness of the surprise question	“For one patient, I thought: they really need it. But for the other two, it’s possible that they pass away but I could see them living another five years as well. But I thought it was needed.” (Quote GP1.2 GP interview 2)
	Some patients with chronic life-limiting illness are not seen by the GP until they approach the terminal phase	“I think it’s especially the people who always see a specialist. Some cancer patients you don’t see for a whole year, but they are monitored by a specialist. I think we miss them. When they have exhausted their treatment options, then they come to us.” (Quote GP1.3 Focus group 1)
	Selection bias by GPs	“But in the group that meets [the criteria], you choose the people you’ve known for longer or with whom you feel comfortable. I would never have asked it of someone I have only seen once in my practice, even if they met the criteria. These are people with whom you feel comfortable, and you know the patient is also comfortable with you.” (Quote GP1.4, GP interview 4)
Effectiveness	Increased GP intention to take initiative in ACP conversations	“I would maybe start it myself, before I would have waited until a patient came to me with something. Now I’ll talk about it myself, even in situations that aren’t urgent, as I just said, because you do it anyway, A bit, a year ahead of time, opening up that conversation.” (Quote GP2.1, Focus Group 1)	Facilitates patients reflecting about future health, values, and wishes	Patient: “You get a different take on things, take on life a little bit. So…” Interviewer: “Yes?” Patient: “You start seeing it differently.” Interviewer: “Yes, and in what way?” Patient: “Yes, what could happen. Or what you’ll be confronted with. That, that, I wouldn’t think about that otherwise, now you think about that.” (Quote PT2.1, Patient interview 11)
	More positive framing of ACP	“What happened to me especially, is that the stories in that workbook, the tendency and the tone of the stories, the positive approach. It’s had an enormous impact. I will take that with me for the rest of my career.” (Quote GP2.2, Focus Group 2)	Wishes are documented and communicated to family	“Well, Dr. [name] made a list together with me […] of what I would and would not want. Every child received that on their computer. So now everyone is aware of the situation, of what I would want.” (Quote PT2.2, Patient interview 10)
	ACP process is facilitated: GPs learn and new and useful information about patients’ experiences and values, document outcomes of ACP conversations	“The experience with illness and dying in their surrounding environment was good to hear, because there were things there that I didn’t know. They are people I don’t follow up for 20 years, I’ve worked in the practice for five years. It’s useful to hear things that also give you insight into why they do or don’t want certain things.” (Quote GP2.3, GP Interview 1)	Positive affective outcomes	Interviewer: “Yes, so that was the value for you, that it’s all on paper now.” Patient: “Yes. That’s a big reassurance for me.” Interviewer: “Yes, yes. So you feel reassured that, uh…” Patient: “That I can count on her if something happens, yes.” (Quote PT2.3, Patient interview 11)
	GPs feel capable to speak up for patient wishes and values	“In the meantime, I’ve been able to apply that a few times, and express it to the family for example. Someone who is palliative and unable to speak anymore, if you can express it that way, you notice it brings about a sense of peace: That’s true, our dad… Then everyone is at peace with it and they stand behind your approach.” (Quote GP2.4, Focus group 1)
	Perception that patients actively contemplate ACP	“I had two conversations, one with just the patient and during the second one I also spoke with the daughter. Those were very useful conversations, where the patient also said: ‘I’m glad I did this. I also actively considered it.’” (Quote GP2.5, Focus group 3)
	Previous experience influences whether outcomes change	“My feeling of being prepared did not change much. Because I actually had that already, since I conducted many conversations for my thesis. That’s mainly building confidence in yourself.” (Quote GP2.6, GP interview 2)
Adoption	GPs feel that ACP, while a delicate subject, is important to do	“[Referring to the goals of ACP] I think that the autonomy people must have regarding their own health, that information, and preserving those fundamental patient rights in an important life phase. I think that is important, because we are coming from a time when decisions were made about and for patients, especially in the final phase of life.” (Quote GP3.1, GP interview 1)	ACP can be confronting and raises negative emotions	“Well, I think we should be open to it, if it can be improved. But for me personally, I thought some things were very confronting. […] I think, one, maybe because of my diagnosis. And two, I think also because of my age. But I admit that there are things I haven’t considered at all. And then a lot of those questions were difficult for me.” (Quote PT3.1, Patient interview 7)
	Not all materials delivered during the training (conversation guide, template) are always perceived as useful	Interviewer: “The template to use is the conversation guide without example questions. Did you use this, before or after the conversation?” GP: “No, that did not add any dimension that would have been meaningful, but which I didn’t already have. […] I only used a piece of what was offered.” (Quote GP3.2, Focus group 2)	Patient supportiveness of ACP	Interviewer: “And how did that come across to you?” Patient: “I supported it immediately.” Interviewer: “You supported it.” Patient: “Yes, because I have a certain opinion about the end of life. Later in my life. And I thought that, I was really, I won’t say enthusiastic to participate but I did it gladly.” (Quote PT3.2, Patient interview 10)
	GPs were unable to schedule conversations	“If you already got it down or if it were less important, you might say, “I’ll just do it quickly and we will see.’ But if you start and it doesn’t go well, then you’re better off not doing it.” (Quote GP3.3, GP interview 3)	Patient appraisal of ACP as relevant or not relevant	“At the moment, I don’t need it. And you don’t know how it’ll be a year from now, or two years from now, or ten years from now.” (Quote PT3.3, Patient interview 2)
Implementation	General satisfaction with the training, but some expectations for more intensive exercise not met	“For me, the interesting part was the discussion and the insight from others. […] Especially the difficulties, the limitations, how they resolve this, sentences to use. Also hearing that others encounter the same obstacles as yourself.” (Quote GP4.1, GP interview 2) Interviewer: “I heard Dr. [name] say, more role-play exercises.” GP 1: “Practicing with concrete case examples, things you can get stuck on and then tips and tricks to get through that.” GP 2: “That’s the advantage of a role-play exercise. You hear each other’s opinions and how someone else would do it, you learn a lot from that.” (Quote GP4.2, Focus group 1)	Satisfaction with form/content of workbook, but sometimes difficult to appraise due to limited recall	Interviewer: “So you have the LEIF-card [pocket card with information about which ADs the person has], and you’ve also looked at the LEIF-booklet [booklet about different ADs]. Do you think that what we gave you, that booklet, has any added value on top of that?” Patient: “Well yes, with a little more explanation about it.” Interviewer: “More explanation, in the LEIF-booklet or ours?” Patient: “In yours it’s more in a language of, how do I want…” (Quote PT4.1, Patient interview 10)
	Workbook is a helpful tool for preparation and during conversations	“But the brochure [referring to workbook] makes the difference, then there is more space to do more in one conversation.” (Quote GP4.3, GP interview 2).	Perceived and desired control over decision-making in the ACP process	“Because at the end of the day we are patients, yes, well, as I say, we don’t speak with a full understanding, we have to undergo it. I don’t know what needs to happen, if suddenly I’m paralyzed, just to name something. Yes, then it’s necessary to help me and I can’t do anything about that, right?” (Quote PT 4.2, Patient interview 4)
	Practical preparation of conversation appointments	Interviewer: “To implement those conversations in your practice, did you have to make any changes? Or do anything differently?” GP: “No, I did that in my free time, so it has nothing to do with my practice. My colleagues had little to do with it.” GP2: “It was the same for me, I also did it on a free afternoon.” (Quote GP4.4, Focus group 1)	Prior experiences with ACP and ADs	“Um, but, and we also filled things out a while ago, and registered it [with the municipality]. That they can’t reanimate. And also with the LEIF-card [pocket card with information about which ADs the person has].” (Quote PT4.3, Patient interview 3)
	Importance of GP self-efficacy	“You have to ensure that you don’t do anything wrong by it. If you frighten people… We talked about that quite a bit. How do you convey it properly? What should or shouldn’t you do? What do you avoid?” (Quote GP4.5, GP interview 3)	Prior relationship with the GP	“Yes, and the difficult part, is that my actual GP here, Dr. [name, GP not involved in the study] […] Yes, they moved to [city]. And yes, that was a little difficult. I can talk to Dr. [GP involved in the study], he was aware of it too, but it’s a little different, yes.” (Quote PT4.4, Patient interview 5)
	Anticipated interactions with patients	“The patient was prepared by reviewing the questions and because you had visited. They knew what was coming next.” (Quote GP4.6, GP interview 4)	Experiences with the ACP conversations: -Positive experience -Bidirectional openness between GP and patient -GP asked questions to encourage discussion	Interviewer: “Did you have the chance to also address what you wanted to discuss during the conversation?” Patient: “Yes, I did. I asked personal questions about that care…the person who then has authority over you. I was able to do all of that.” Interviewer: “Did you feel like your GP listened to you and showed understanding for what you brought up?” Patient: “Yes, I did.” (Quote PT4.5, Patient interview 1)
	Experiences with the ACP conversations: -Patients did not all use workbook to the same extent, which affects conversation -Themes differ from patient to patient -Difficult for some patients to understand topics	“With one patient I talked at length about what she would want in terms of care later, hospitalizations and the like. With another patient it was primarily about what was important to her in this moment and what she definitely wants to maintain, which is contact with her granddaughter. So it differs per patient.” (Quote GP4.7, Focus Group 2)	SDM presence during the conversation	Interviewer: “Can you tell me about how that conversation went?” Patient: “It lasted about an hour and I thought it was good that my spouse was there as well. She might have had more questions to ask than I did.” (Quote PT4.6, Patient interview 9)
(Intention for) Maintenance	Changes to training for sustainable implementation	Interviewer: “Dr. [name] is saying a little further on in the master years, but also the GPs who have been working for a bit longer and are interested in refining their skills.” GP: “The basis is the attitude. If you’re focused on […] it all has to happen in those thirty minutes, someone who’s really focused on that, they won’t get anything out of [a training]… Yeah.” (Quote GP 5.1, Focus group 2)	ACP perceived as completed vs. intention to maintain ACP with the GP	Interviewer: “And when would you like to talk about it again with Dr. [name]?” Patient: “Well, eight days from today she’s coming over.” Interviewer: “Ah yes, so when she comes over again, you’ll talk about it again?” Patient: “Definitely, yes.” (Quote PT5.1, Patient interview 10)
	Patient workbook is a useful tool for future practice application	“I would especially like to keep using the workbook, I put the overview for doctors on the computer so I can look at it. I think the booklet is useful, I would give that to a patient if they started talking about [ACP] during a consultation.” (Quote GP5.2, GP Interview 2)	Wanting to discuss ACP with other health professionals/specialists	Patient: “And I would like to also have that conversation with my nephrologist. But yes, of course, you can’t just do that, just demand that from her as a patient […]” Interviewer: “Yes, that asks a bit more planning because their time is more limited? If I understand correctly.” Patient: “Well, the thing is, you can hardly sit and talk for an hour with the nephrologist […] Just to say what you would want or what your wishes are, and to learn more about how, what they do, at their level.” (Quote PT5.2, Patient interview 6)
	How to plan and conduct ACP efficiently within limited consultation time?	“I think the added value has primarily been that we made time for it. That’s where there will always be problems. You should have that conversation with patients very often, but then we won’t set aside an hour for it. That’s the added value for the patient now: you’re really making time for it and letting them talk. In normal circumstances it’ll rather be: “We’ll talk about it some other time”. That’s my concern.” (Quote GP5.3, Focus group 1)	Plans to revisit ACP conversations when health or quality of life changes	Interviewer: “Are there moments where you think: at that moment, it would be useful to have that conversation again?” Patient: “I think so. If I’m not doing well, I think I’ll need it. I feel good now, but you don’t know how long or what… We will see if the medication works. If the moment comes, then it’s alright.” (Quote PT5.3, Patient interview 9)
	Interprofessional: Feasibility and desirability of task delegation within the practice	“I find it difficult to split something like that up. It doesn’t seem pleasant for the patient to first have a conversation with me, and then with another colleague.” (Quote GP5.4, GP Interview 4)	Need for more community/media support	“I think a media campaign could actually help. I think so, personally. Because people wouldn’t talk about it, and if you encourage people by saying ‘talk about this topic with your GP’, or ‘[your GP] may address this soon’, without it being…dramatic, and without it, uh… meaning that everyone is going to be terminally ill. [laughs]” (Quote PT5.4, Patient interview 3)
	System-level: Need for a structured and unified system to document ACP conversations and ensure transfer of information with other clinicians	“I think there should be more possibilities in our software, just like we can fill in other parameters now. That it’s much clearer. Now it’s something separate, and where do you have to write that? A document somewhere in the file, or scan it, because it’s not clear when someone else opens that file. Something very simple, a step-by-step plan, which is very clearly visible in the file.” (Quote GP5.5, Focus group 1)