Table 2.

Content and structure of the optimized message

What we can do	What it involves	Language tested	Why it works
Acknowledge doubts and distrust	Validate concerns about past and present injustices	“We know that a lot of people have questions—and even concerns—about giving permission for their genes to be used in research. And studies have shown that, in general, concerns among ethnic minorities can be even greater. And there are real reasons for this. Some are connected to personal experiences and some to historical injustice. These concerns are real.”	“It makes me feel a bit more seen, that they can understand and that they have some appreciation for other points of view … Especially in contrast to [the previousmessages], where it was almost good to get as many people to donate, it is a lot more nuanced [this updatedmessage] that still outlines the benefits.” (Participant self-identifying as from the Black African group) “Acknowledgment that ethnic minority people are very skeptical, acknowledgment that in the past history, that this particular client group has been not treated fairly in regards of treatment for health wise. So, I think acknowledging that, I think that has been positive. So not ignoring the past. (Participant self-identifying as from the Black Caribbean group)
	Validate doubts due to a lack of familiarity with genomics	“If you’re wondering what genetic testing is all about, you’re not alone. Healthcare can be confusing enough as it is, and it would be surprising if people didn’t have questions about things like DNA testing”	“You can resonate with it because you know, when you asked us at the start all these questions, a lot of us, we really didn’t know anything about it. So it makes you feel more accepted by the fact that you have kind of no knowledge or not very broad knowledge on the subject.” (Participant from the disadvantaged socio-demographic group)
Empower people	Frame it as a voluntary choice	“It is your health, your genes, and your choice.”	“I think it is right. It is my choice. It is almost like there is no pressure, really.” (Participant self-identifying as from the Black African group)
	Emphasize control where relevant	“The most important thing to know is this: you control whether you share your genetic information with others. One reason to do so is to receive better healthcare. In this case, the results of a genetic test will remain private, just like your other medical records, and only you and your doctor will have access. Another reason is to volunteer to have your genetic information used in research for new treatments. In this case, your genetic information and your medical history is protected in a secure database.”	“I think it’s good that you have a right over it, so it’s not just like they just take it and then you give it to them and they can do whatever they want. You still have your say in it.” (Participant from the disadvantaged socio-demographic group)
Calm concerns	Avoid emphasizing novelty. Instead, ground genomics in what is familiar	“Today, your doctor can use a simple blood test to uncover a universe of information, like your red blood cell count or your cholesterol. In much the same way, they can look at your genes to get a more complete picture of your health, like your risk for developing certain conditions. Ultimately this extra information means they can make better decisions for you and with you. Genetic testing isn’t a replacement for the tools doctors use today, it’s just one more piece of information that works alongside everything else”	“I thought it was interesting. The part where it said it might be unfamiliar for you to hear about it, it’s just like other tests and the reassurance it’s giving you the best care possible, I think that was quite reassuring and also the fact that it was just saying we just want to improve ways in trying to make your health better.” (Participant self-identifying as from the Black Caribbean group)
	Build some context around it: be specific about what is and is not involved	“When you put your genetic information into the care of a doctor or a researcher, it still belongs to you and you have a say in how it’s used. That right is protected by several different laws that were created to make sure your data is handled securely and responsibly … The main way the privacy of your data is protected is by restricting who can see it. When you take a genetic test for medical reasons, only members of your care team—like your doctor—can access the results.”	“In a way it was very reassuring, and I think it was the first video that actually talked mostly about the security and mostly about not to get you in some way, but to reassure you and protect your information, and I wish it was something like this from the beginning. I would feel much more reassured and much more secure.” (Participant from the disadvantaged socio-demographic group) “I think that’s one of the questions I probably had in my head, to be honest, throughout this session was whether our identity would be anonymized when it’s going to researchers. So, that’s quite good to know.” (Participant self-identifying as from the Pakistani group)
Introduce benefits after the preparatory work above has been done	Move to personal benefits by articulating the specific relevance for the target audience	“It’s important you get the information you need on why you might—or might not—want to consider opting in to sharing your genetic information to help create better, fairer, and more personalized medicine for you and your family, and families like yours.” “When scientists are able to compare more people from many different backgrounds, they can gather more insights and, over time, help more people.”	“It did mention family a bit and that sounded more like immediate family. I can resonate with that quite deeply to be fair. It’s a bit like it would benefit me, benefit my immediate family, my loved ones around me, and then the future.” (Participant from the disadvantaged socio-demographic group) “People like that, who aren’t rich, middle-class: are they also going to benefit from this? Because at the end of the day, that’s where I came from, to where I am now, and I would like for my import not to be disregarded just because of race or what your class is … So, me helping gather DNA, I would like people from my roots to also benefit from this.” (Participant self-identifying as from the Pakistani group)
	State concrete, tangible benefits and (where possible) incorporate specific examples	“In the near future, we’ll be able to use a bit of blood or saliva to do a DNA test. The results of this test can mean less guesswork and the ability to diagnose diseases like breast cancer earlier and more accurately. And the more people who share their DNA for researchers to study, the more medicine can be precisely designed to work for you and your family.”	“I like it. I thought it was the strongest out of the ones that we’ve seen so far. They try to appeal to you as an individual. They explained what it was going to be used for. They also dropped in the C word, which most people know somebody or has some kind of connection with that. That kind of makes like your ears prick up more and you pay attention.” (Participant self-identifying as from the Black African group)
	Finally, nod at the bigger picture by appealing to wider, collective benefits	“If you do participate, your doctor can spot patterns and learn more about how they affect your health by comparing your genes with people who share a similar heritage. The result is better healthcare for you and others in your community.”	“Well, probably it was not more motivating for me personally because obviously I’m not a minority ethnic group, although my husband is. Not for me, but it gave me a better feeling about the whole project, maybe. Yes. I’d say it does make me feel a bit more positive about the whole concept of it.” (Participant from the disadvantaged socio-demographic group)