TTHealthWatch is a weekly podcast from Texas Tech. In it, Elizabeth Tracey, director of electronic media for Johns Hopkins Medicine, and Rick Lange, MD, president of the Texas Tech University Health Sciences Center in El Paso, look at the top medical stories of the week. A transcript of the podcast is below the summary.
This week’s topics include household transmission of COVID tracked with EHRs, a single dose vaccination study, providing housing to reduce hospital admissions due to COVID, and the burden of CVD and death relative to glycemic indices of foods.
0:38 Household transmission and the EHR
1:39 7,300 index cases
2:28 Is scalable
3:14 Providing housing for homeless with COVID
4:15 75% men
5:15 Moved from EDs or sheltered areas
6:15 Comprehensive approach
6:28 Single-dose COVID vaccination
7:28 Reduced death by 50%
8:33 Take any vaccine you can
10:10 Higher BMI
11:10 Attributed to how much foods raise sugar
Elizabeth Tracey: Can providing housing reduce the burden on hospitals of COVID-19?
Rick Lange: Household transmission of COVID.
Elizabeth: A worldwide look at glycemic index and its multiple consequences.
Rick: And the early effectiveness of COVID vaccines.
Elizabeth: That’s what we’re talking about this week on TT HealthWatch, your weekly look at the medical headlines from Texas Tech University Health Sciences Center in El Paso. I’m Elizabeth Tracey, a Baltimore-based medical journalist.
Rick: And I’m Rick Lange, president of Texas Tech University Health Sciences Center in El Paso, where I’m also dean of the Paul L. Foster School of Medicine.
Elizabeth: Rick, I think I’d like to start with JAMA Network Open. This is a research letter that you’re going to take a look at, looking at household transmission of SARS-CoV-2 and how the electronic health record may help — even supplant — contact tracing, potentially.
Rick: Yeah. That’s probably the biggest virtue of this particular study. We’ve reported before about household transmission, but that’s really time-intensive to figure that out. You have to identify the contact and identify people around them. It just takes a lot of work to do that, so doing that in thousands or tens of thousands of people is very difficult. But this particular research took a different approach.
It was centered at the Mass General Brigham system. It’s obviously a large integrated hospital and ambulatory care network. It’s based in Boston. They did this purely from the medical records. No participant contact tracing was required for this study. They used home addresses that were recorded in the electronic medical records so they could identify the index case and who else in that same family or that same address had also been infected.
So they identified about 7,300 index cases and they linked those to almost 18,000 additional at-risk individuals that were assigned to that exact same address. Now, those were about half females and half males. About a third of those resided in households of up to 6 to 10 individuals, and what they discovered was there were over 1,800 cases, or about 10% of household contacts, actually developed COVID infection.
Now, the median time from when the index case was reported to the second was about 3 days, so whether it was actually transmission or whether they had the same contact was very difficult to tell, but they were also able to look at some of the risk factors associated with a higher transmission rate, and it’s those individuals that were age greater than 18 and those that had multiple comorbid conditions. That’s very consistent with what we reported previously, but the novelty is how they achieve these results.
Elizabeth: Yeah, and this is scalable. I mean, this is something that could be adopted by certainly large academic medical centers probably, right away, and even penetrate down into smaller centers.
Rick: Absolutely. Again, you’re using electronic medical records and I’ll take it a step further. If you don’t use just a single system for EMR, electronic medical records, but if you have a health information exchange — because the individuals could be seen at different hospital systems — it even expands your knowledge even more.
Elizabeth: Yeah, so I like the novelty of this a lot. This issue of contact tracing, of course, is not one that’s going to go away. It’s been persistent in public health for a very long time, and if there’s a way to facilitate that utilizing some of these electronic tools, that seems like a win-win.
Rick: Yeah. Instead of getting more people, let’s get smarter about how we accumulate and analyze the data.
Elizabeth: Exactly. Since we’re in JAMA Network Open, let’s stay there. And this is something that really speaks to my heart and this is this idea that, gosh, among people who are homeless, COVID-19 infection, of course, occurring at a very high rate. In San Francisco, they said, “Hey, if we house these folks, what will happen to our hospitalizations?” So that was their primary objective for this, but it turns out that it had a lot of other multiple benefits.
For March 19th to May 31st, 2020, they had five what they called isolation and quarantine hotels, 1,009 hotel guests in these. They had a team approach where a physician-supervised team of nurses, healthcare workers provided round-the-clock support, including symptom monitoring, wellness checks, meals, harm reduction, and medications for opioid use disorders. They really took a very comprehensive approach.
Among these folks who were in the hotels, their median age was only 44 years. 75% of them were men, and in San Francisco, of course, 45% were Latinx. Of this number, they were able to determine other things that were going on with these folks. Noteworthily, 25% of this population had comorbid mental health conditions and 26% had substance use disorders.
What they found was that there was a non-significant decrease in the mean hospital length of stay for inpatients with confirmed or suspected COVID-19, and it declined from 5.5 to 2.7 days. So supporting people experiencing homelessness during this pandemic, they were able to scale this model and they were also able to really hang on to the vast majority of these folks. My hope, of course, would be that they would stay in care since they were already there.
Rick: A lot of information that comes out of this. One, is that you can do this — it’s scalable. There were over 1,000 individuals in that 10-week period that they moved from emergency departments or sheltered areas — these were people that either had COVID or were suspected of having COVID — to move them into areas where they could receive personalized care and do it safely. It was about 80% stayed the entire time until they were either recovered or cleared. That’s pretty remarkable.
The second is very few of these individuals actually ended up in the hospital. It was about 4% of these individuals ended up being hospitalized. Now, otherwise, when they’re sitting in an emergency department or a shelter home, they would have been sent to the hospital and had to stay there, either to receive their care or to be quarantined or isolated until it was determined whether they were infected.
The number of individuals that were required to care for these patients was relatively small. It was 1 to 3 nurses for every 50 homeless individuals that were sheltered, and a physician as well, so great news. It provides care to these individuals that are the most vulnerable and also helps to prevent unnecessary hospitalizations and spread of the disease at the same time.
Elizabeth: This comprehensive approach that they took to both the substance use disorder and the mental health disorders would bear fruit over the long haul, I assert.
Rick: Yeah. We’re to remind our listeners that there are half a million people in the United States that are sleeping homeless every night and these are the individuals that we’re talking about.
Elizabeth: Let’s turn to a preprint. This is taking a look at a single dose of an mRNA vaccine and that efficacy related to it.
Rick: This is really the first real-world evidence of COVID-19 vaccine effectiveness against symptomatic COVID-19, older individuals in the United Kingdom, specifically the Pfizer vaccine and the AstraZeneca vaccine. Now, these are both vaccines that require two doses.
The U.K. handled this little bit differently. First of all, with regard to the AstraZeneca vaccine, they’ve only administered the first dose. Then with regard to the Pfizer, they didn’t have enough to give everybody two doses, so they’ve decided to give the first dose and prolong the time period to the second dose, so what we’re reporting here is the effectiveness just after a single dose of Pfizer or AstraZeneca.
The single dose of the Pfizer vaccine is about 60% to 70% effective at preventing symptomatic disease in adults age 70 and older. Even in those that went on to get infected, it reduced the risk of hospitalization by 44% and reduced the risk of death by about 50%. Now, with regard to the AstraZeneca — again, just a single dose — it was about 60% to 75% effective, and again, a 50% decrease in death and a 37% decrease in emergency hospitalization.
The benefit accrued in both of these about 14 days after the vaccine was administered, but it does show that even though two doses give you maximal benefit, that there’s still significant benefit after the first dose.
Elizabeth: I would remind you that, of course, Anthony Fauci came out once again advocating for two doses of the mRNA vaccines regardless of this data.
Rick: Yeah. It’s just how different countries handle it. The U.K. said, “Listen, we would rather get everybody vaccinated with at least one.” In the United States, we’re saying, “Let’s get maximal effectiveness and make sure that everybody gets two vaccines, and let’s try to do everything you can to encourage increased production.”
Elizabeth: Of course, we would be remiss in not noting that on Saturday the J&J vaccine got an EUA and that’s going to be spread out all over the country too. I’d just remind folks that regardless of what you see as reported efficacies for vaccines, really, you need to take whatever vaccine you can get as soon as you can get it.
Rick: That’s great advice.
Elizabeth: And I noted, also, this morning that there’s another one that’s in the ranks that it looks like it may end up with an EUA in May, and finally, that if you’re feeling any vaccine hesitancy, really, you ought to go out and get one because these variants are emerging very quickly.
Rick: As you said, the most important thing is to get a vaccine. They’re all effective and they’ve been studied in different populations. Delaying getting vaccinated because you want a particular one, not good advice for the reasons you’ve mentioned.
Elizabeth: OK. Let’s turn to the New England Journal of Medicine since we’re talking about worldwide issues. This study was really … is a huge ongoing study and it’s looking at glycemic index, glycemic load, and cardiovascular disease and mortality. In this analysis, they had over 137,000 people between the ages of 35 and 70, living on 5 continents, with a median follow-up of 9.5 years. I think that’s pretty remarkable. Don’t you?
Rick: It is. Keep going.
Elizabeth: What they did is looked at a lot of food questionnaires. They had 7 categories of carbohydrate foods. They calculated, based on a number of things, the glycemic index relative to those foods, the consumption, and then they looked at deaths and cardiovascular events that occurred during this follow-up period.
No surprise, the high glycemic index was associated with increased risk of death, increased risk of major cardiovascular events or death, both among participants with pre-existing cardiovascular disease and those without such disease, was noted. The other thing that was not surprising, of course, was the higher your BMI and the higher your consumption of high glycemic index foods, that put you in the worst risk category.
Interestingly, also, to me, other confounders like cigarette smoking, use of statins were not associated with an increased risk relative to glycemic index. Let me just note one final thing. This is the prospective urban-rural epidemiology or PURE study and this is the first time I’ve heard of it.
Rick: For our listeners that may not be familiar with glycemic index, what that means is if you take 50 grams of particular food and the individual eats it, how much does it raise your blood sugar? Carbohydrates have a high glycemic index.
The value of this particular study, as you said, it’s almost 140,000 individuals. Secondly, it was conducted in 20 different countries on 5 different continents.
Everybody eats different kinds of food. This isn’t attributed to a particular food, but it’s attributed to how much would a particular food in whatever country you eat it raise your sugar. It transcends dietary habits and it’s more associated with the glycemic index. Those things make this particularly novel. The glycemic index really does make a significant difference. It doesn’t matter what country you’re in or what continent you’re in, it’s important.
Elizabeth: I thought it was really interesting that apparently there are two different indices that are used for this. One is what they call the white bread index and the other one is straight glucose.
The other thing that I would advocate for is I really think we need more education about glycemic index and I think that on our food labeling we ought to include some kind of a metric about that because there’s a lot of confusion about it. I can be confused about it, so I think it would be really great to have that on there.
Rick: Yep. It’s very different than calories, for example, so I totally agree. That information can transcend particular countries or particular diets or particular food groups. I think that information would be very helpful, and now this study, clearly it ties it to cardiovascular disease and mortality.
We know that also eating of the low glycemic diet decreases your risk of developing diabetes and other — I’m going to call it inflammatory — conditions as well. Elizabeth, I agree with you. It would be a new concept, but very valuable.
Elizabeth: On that note then, that’s a look at this week’s medical headlines from Texas Tech. I’m Elizabeth Tracey.
Rick: And I’m Rick Lange. Y’all listen up and make healthy choices.