SuperWIN Trial of Retail-based Dietary Interventions Wins on Many Levels: Dylan Steen, MD, Explains

SuperWIN, the Supermarket and Web-based Intervention Targeting Nutrition clicnial trial, found that dietary and nutrition counseling provided to primary care patients in the aisles of local supermarkets improves overall quality of food choices, measured here as improvement in participants' DASH (Dietary Approaches to Stop Hypertension) score.

The model, which could eventually be scaled to meet diverse community needs, is essential to investigate given that the 75% of Americans across socioeconimc strata live with poor dietary quality, according to coprincipal investigator cardiologist Dylan Steen, MD, MS, director of clinical trials and population health research at the University of Cincinnati Heart, Lung & Vascular Institute. The problem, he added during an interview with Patient Care Online, is "rampant" and drives an overwhelming amount of global morbidity and mortality.

The study, a collaboration with Kroger supermarkets, tapped the expertise of Kroger store-based dietitians who reviewed individual participant's food purchase data and provided guided tours of store aisles while providing nutrition education. Some participants also recieved initiation to online grocery shopping apps designed to build nutritional awareness.

Dr Steen describes the population, the intervention, and the promising results in this short video.

Dylan L Steen, MD, MS is adjunct associate professor, director of clinical trials and population heatlth research at the University of Cincinnati Heart, Lung & Vascular Institute, University of Cincinnati College of Medicine.

The following transcript has been lightly edited for clarity and style.

Patient Care Online. I'm Grace Halsey, senior editor of patient care online. And I'm speaking today with cardiologist Dr Dylan Steen about findings from a first of its kind study that he just led called the Supermarket and Web-based Intervention Targeting Nutrition, or SuperWIN, study. He just presented the results at the American College of Cardiology 2022 Scientific Sessions.

Welcome Dr Steen.

Dylan L Steen, MD. Thank you so much. And I'm lucky to be here. I have wonderful co-principal investigator named Dr. Sarah Couch who is a nutrition expert and then a whole team of other co-investigators with specialties in different areas. And our Cincinnati Children's Hospital is also involved along with UC, so a wonderful team, but I'm happy to represent them

PCO. SUPERWin was a start. Would you tell us about the study?

Steen. We worked with the Kroger Company. For those of you who may not know, Kroger is the nation's largest supermarket chain, with over 2200 retail spaces, and then over 225 retail clinics.

The first problem we went after was poor dietary intake, 1) because Kroger has a full food inventory and 2) because 75% of Americans have what is classified as poor dietary quality. It is rampant whether you're high or low socioeconomic status, there's a huge prevalence of poor dietary intake. We designed was a randomized controlled trial, because we wanted to really understand causality of these new and novel interventions that we were going to study. Did they work? How well did they work? How long did the effects last, etc. So it was sort of low hanging fruit--the obvious first thing to go after.

We brought participants who were members of UC Health at the University of Cincinnati Health primary care network. We invited them to participate in this trial. The participants were all adults. They had to shop at one of our Kroger's market locations. We have a variety here in Ohio and Kentucky. Participants had at least one cardiovascular risk factor eg, obesity, hypertension, high cholesterol. They had to be the primary shopper or meal planner in the household. They were not however, online shoppers before they came into the study. These are people who like to go into the store. And then they had to be willing to follow the DASH diet dash. I'm talking to a primary care community. You all know this well, but it's one of the most evidence-based diets and very similar to the Mediterranean diet. But we have a very hard time getting the public to adhere to it in even a modest amount.

There were 3 study arms. One arm was the Control group and they received a medical nutrition therapy (MNT) visit, so, standard of care. Now we enhanced it to our standard of care which was much better than what is delivered in traditional medical settings and most of that is because of the store infrastructure and the different things we had in this study.

In the second arm, which is called Strategy 1, we brought participants back for 6 additional visits on top of the medical nutrition therapy. And we actually had the dietitians and the participants look at the participant's own individualized purchasing data. Your dietitian would know what you bought, and could say, “Gee, okay, so you like to eat these things. All right, I get it, I get it. But these are things maybe we could change, maybe these are things we could improve,” etc. Very helpful. And then we actually used that to guide them through ins in the aisles tours of the store. So actually taking them into the aisles of their preferred Kroger store. So right where they go every single week to shop anyway.

And then the third arm incorporated all of that and also introduced these participants to what we called "online enhancements." So shopping on, getting home delivery using different nutrition applications like Kroger's or Yummly, to better plan meals, better prepare healthier meals, and make better choices for them. The reason we wanted to introduce participants to these [online enhancements] was that these were folks who had, by nature, not elected to use online shopping in the past. And we know that many consumers out there have bad experiences the first time they try these. So the Kroger dietitian, being a Kroger employee was able to introduce then them, show them how to use these things to improve their health, and make sure that they had a good experience out of the gate. So three different arms, each one with sort of a higher intensity of the intervention.

PCO. What outcomes were you looking for and what happened?

Steen. So this was a study where we were first focused around dietary quality, that was our primary endpoint. So as you all know, you've looked at many studies, each study has to pick what it's going to target. So this was the DASH score. The DASH score, a zero- to 90-point score, is a measure of adherence to the DASH diet. So 90 is perfect adherence. Hardly anyone eats that. Zero is absolutely no adherence. And basically, its components include all the different things that we want in DASH. For example, you get points for eating the FDA-recommended amount of fruits and vegetables that you're supposed to in DASH for your caloric intake, or for consuming more low fat dairy, as opposed to high fat dairy, or more whole grains as opposed to total grains, for lowering sodium, for lowering sweets and oils and things like that. So it's constructed of a bunch of component scores, each of which reflects one of the things that the DASH diet prescribes. We calculated raw dietary intake data. We had an exceptionally scientifically rigorous way of assessing DASH, especially in comparison to previously published things, so a very, very good measure. We we didn't use food frequency questionnaires.

The results at 3 months from baseline, we saw that every single group increased their DASH score, and increased their DASH score significantly. In plain English, that means every single group was eating better, significantly better. Even the control group, their DASH score went up by 5.8 points. That doesn't sound like much, but that is a lot. And my co-principal investigator, Dr Couch, having done a lot of DASH-related research in the past, has tested what happens in traditional medical settings if you give MNT and there's really no effect. So you see how much better our control was than what we do. We['re doing standard of care, but we're doing it in a better environment, with a dietician who knows all the retail products. What we saw in Strategy 1, which was like the intermediate dose, there was a greater increase in DASH than in the control, so we saw improvement from these in-store-person-guided scores. For the final one, Strategy 2, that also included the online enhancement, we saw even the biggest change in DASH score. So really, really convincing changes that were quite wonderful.

The first test in terms of statistical testing that we did was to combine Strategy 1 and Strategy 2 and compare them to control. And what we were doing with this test was trying to understand whether these in-store personally guided in-the-aisles tours, 6 sessions of them, how much they improved DASH diet compared to control. And it turns out it is by almost 5 points just by doing the tours. So that's clinically meaningful. It was very statistically significant. And that was our primary hypothesis.

We were using what we call hierarchical testing, because we hit our first hypothesis, and because we were significant there, we were allowed to test a second hypothesis. And that was Strategy 2 versus Strategy 1. Now, if you remember, the only difference between those 2 was that Strategy 2 got the online enhancements. And it turns out, yes, well, that's also effective. So even for people who are late adopters of online shopping, those people that haven't chosen to online shop before or use these tools, it turns out if you introduce them to them, if you train them on how to use them, that in fact increases their dietary intake quality, even more. So we really understood quite a lot about this, not only that each group gets substantially better but we also answered these 2 important scientific questions that yes, in-store tours really do work and that the online enhancements increased DASH quality, or DASH adherence even further beyond it.

And then when you look at 6 months—6 months was the second time point, and that was 3 months after participants had finished any dietary education—at that stage we saw in the control arm, that there was still an increase in DASH score, but it wasn't statistically significant anymore. And that's not unusual, right? They only got one educational session. It really helped. But it [the effect] waned a little bit with time. What was interesting is Strategy 1 and Strategy 2 were still highly significant. That's really important. So you'll see if you look at the slides, or when the paper comes out, you'll see what the confidence intervals are. But there was persistence, not quite as high as the 3 months, but still quite persistent, at 6 months, 3 months after the intervention, that is very, very encouraging.

In terms of looking at between group differences, that same test that we did at 3 months, the between group differences were no longer significant. But to me, that's not the main takeaway. The main takeaway is we know that tours work, we know that online enhancements work. And in fact, for each intervention group, other than control, DASH score was still significantly improved at 6 months, compared to baseline, which is wonderful. That's what we've been shooting for.