Table 2 Overview of themes and sample quotes from Phase 1 – Interviews

No reflection on screening benefits and harms; potential harms are seen as disproportionate to the main perceived benefit of early detection of BC, but self-examination is also considered important

  [About BC screening] If I were to be screened, I think that would bring some reassurance. That I would just know that I did everything I could to keep an eye on myself, but that it is also well monitored from the outside

43 years, high education, unknown HL

  [About the main benefit of BC screening] If there is an abnormality, you have an earlier chance of discovering it and you have a better chance of surviving it

43 years, middle education, high HL

  [About BC] I always think of that good friend of mine. Well yeah, I know the impact it had on her life. Still has. She will never be the same again. She has … she has also had the whole hassle, so to speak. She first.. they did chemo first. Then she had surgery and then she also had radiation, so her energy level has gone. She is one year younger than me and she actually has no choice other than to use a mobility scooter

40 years, middle education, high HL

  [About the considerations regarding BC screening participation] I think it’s indeed… it’s been on my mind for so long at my age that I … Yeah, my mom and mother-in-law, they all do that, so I don’t know any better than that your turn will come eventually

45 years, middle education, low HL

  [About the considerations regarding BC screening participation] I’m more like it’s good, you know that. It is, it’s how it’s supposed to be

43 years, high education, high HL

  [About the potential harms of BC screening] Well, not for me, but I know that it causes stress for a lot of people… Just the fact that the bus is in the neighborhood stresses quite a few people out. I think that’s the only disadvantage I can think of

47 years, middle education, high HL

  [About the potential harms of BC screening] Yes, I hear that it’s painful. And that’s no reason for me not to do it. Because when I look at my friend, she’s in a lot of pain right now, but that’s because of the reconstruction surgeries. Then I think, then it’s better to have discomfort in advance than the pain caused by perhaps intervening too late

43 years, high education, unknown HL

  [About self-examination] I think if I feel something in my own body then I’ll go to the doctor to get it checked. So the chances of getting it are nil. Look, if I didn’t do anything about it, I’d say ok. But I feel my own body and I know exactly what’s right and what’s not… Then I go straight to the doctor if it’s not right

47 years, middle education, low HL

Risk perception: lacking knowledge about breast density and absolute BC risk

  [About BC risk] My mom doesn't have it. She's 85, so yeah, I don’t think straight away that I'm in a risk factor or anything

47 years, low education, low HL

  [About BC risk factors] But it’s also our prosperity. [Interviewer asks what the interviewee means by prosperity] A rich man’s disease, just excessive drinking, excessive smoking, our Western consumer society

48 years, high education, high HL

  [About pregnancy] Well, the mammary glands and all. I mean, yeah, that changes. The nipples themselves change a lot after breastfeeding, for example. Yes, I can imagine that might trigger something. And well, also perhaps the hormones that are produced. Although I can also imagine that nature will also protect mothers a little more

40 years, middle education, high HL

  [After the interviewer asks whether breast density is a risk factor] No, I don't expect that. Look, being more flexible, you can feel in depth. But one person has strong muscles and the other weak ones, that's how I look at it

45 years, middle education, low HL

  [About general BC risk] You hear breast cancer quite a lot of course. One out of three?

45 years, middle education, high HL

  [About personal BC risk] I smoke, yes, then I would expect the risk to be higher. But really a lot higher? A little but not very much

45 years, middle education, low HL

  [About personal lifetime risk perception] Well, I guess just 50/50, so 50%. You either get it or you don’t. [Question on risk perception over the next 10 years] Yeah, I think it might be just a little bigger. Then it’s 60/40 because you’re getting older

41 years, middle education, high HL

  [About the participant’s personal risk perception] Very unpleasant to think about. I really don’t dare say anything. The idea…, jeez. I wouldn’t say anything about that…, I just think you’ll bring it upon yourself when you.., I think so much…, no I really have no idea!

43 years, middle education, high HL

  [Interviewer: Is that lifetime chance greater or smaller than in the next 10 years?] Smaller chance, because it’s a longer period

47 years, middle education, low HL

Beliefs towards risk-based screening are positive, women believe that it will identify personally modifiable risk factors

  [About risk-based BC screening] I think it's progress, also partly, how do I explain that, self-awareness, it's nice that you get that chance, that's how I see it. But when you get assigned to a group later on in the future, that’s also, self-responsibility, that's what I actually mean, that you also have to do something about it yourself, so to speak

42 years, middle education, high HL

  [About risk-based BC screening] I think the benefits are really the awareness that, that it’s… It’s not our fault at all, but that you can contribute a little bit to a healthy lifestyle. And yeah, that people are made aware of it, or that we can be made aware of it

45 years, middle education, high HL

  [About risk-based BC screening] I'm positive… I'm positive about it. (…) Yeah, because to know if you're more at risk or something.. Yeah, those are things you'd want to know anyway. But I personally think the risk is small, so…But to get it…[Interviewer: confirmed?] Confirmed I.. maybe I would do it then

47 years, middle education, low HL

  [About the lower screening interval for those at low risk] Less often, I would think it’s not completely fair. I don’t drink, I don’t smoke, I practice a super healthy lifestyle, I’m at a healthy weight, there’s nothing in the family, so I’m assigned to the low. And then suddenly I get to come less often. Then I would be tempted to change that slightly, that screening test. If it’s every five years for everyone and then all of a sudden they tell me you don’t have to come so often, so you do it every seven years, I wouldn’t like that

42 years, middle education, high HL

  [About a questionnaire to measure risk factors] The only thing… I always think such a questionnaire is of course just what the person wants to fill in. You always paint a rosier or a worse picture of yourself, so it's always difficult to fill it in very clinically honestly. You can always say 'drink very little' but yeah… 'it's not too bad'. It’s very difficult to say exactly: I really fall within this risk behavior, I think

43 years, middle education, high HL

Explicit information needs include wanting to know why one has been assigned to a certain risk category and wanting advice on risk reduction

  [About receiving the result of risk-based BC screening] Yes, especially how those pillars are constructed. What makes someone ‘a high risk’, for example? Why average? Or why low? So that it’s well founded. That the factors that are taken into account when coming to a certain decision are clearly explained. So that you don’t get any horror stories, but just get a clear explanation of why a certain route has been chosen

43 years, high education, unknown HL

  [About receiving the result of risk-based BC screening] Yes I would really like some advice on how… what can you do to reduce that risk? And that doesn’t mean that you won’t get it, but it falls into the category that you can do something about it yourself

40 years, high education, low HL

  [About receiving the result of risk-based BC screening] And what I ‘d like then [when at high risk], I think I would like it if there was a telephone number or a consultation hour, or somewhere to go or something, or to your own GP, or come to you, for example, to give me advice

43 years, high education, high HL

  [About receiving the result of risk-based BC screening] What’s also a good thing in those brochures, an overview of breasts with abnormalities that could indicate breast cancer. I think that’s a very clear, yeah, model. I think that also helps for those intervening years. You can also do something yourself, just feel and see if anything changes in your breasts. And then make that call yourself, not relying entirely on breast cancer screening

40 years, high education, low HL