PodMed Double T 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 PT after knee arthroscopy, management of hypertension in people with diabetes, mammography in older women, and a measles update.
0:48 Measles update
1:48 90% haven’t been vaccinated
2:50 Titers may not prove immunity
3:10 Mammography in older women
4:11 Understanding what is the best screening technique
5:15 Women should have a screening
6:11 USPSTF says there isn’t as much evidence
6:49 Blood pressure in patients with T2D and heart disease
7:50 Almost 11,000 patients
8:53 Rehabilitation after knee replacement
9:53 No important difference in patent reported pain
10:50 Bundled payment
11:30 More motivated as inpatient?
Elizabeth Tracey: If you have to have your knee replaced, does it matter whether you have PT in the hospital or at home?
Rick Lange, MD: At what blood pressure should you initiate therapy in people with diabetes?
Elizabeth: If you’re an older woman, what techniques should be used for screening mammography?
Rick: And do you need another measles vaccination?
Elizabeth: That’s what we’re talking about this week on PodMed TT, your weekly look at the medical headlines from Texas Tech University Health Sciences Center in El Paso. I’m Elizabeth Tracey, a medical journalist at Johns Hopkins, and this will be posted on May 3rd, 2019.
Rick: And I’m Rick Lange, President of the Texas Tech University Health Sciences Center in El Paso, where I’m also dean of the Paul L. Foster School of Medicine.
Elizabeth: And I’m going to start out, Rick, this week, by thanking you for being flexible. I would like to start with the measles outbreak, and in contrast to our normal behavior, this is not an update that’s based on a study. Instead, this is based on the fact that there’s just a lot of stuff going on with measles, and it’s all to you.
Rick: This is a report from the CDC to alert everybody that since the beginning of the year, through April 26th, this past week, there have now been over 700 individual cases of measles that have been confirmed in 22 states here in the U.S. This is the greatest number of cases reported in the last 25 years and since measles was declared eliminated in 2000.
Now, why do we have measles if, in fact, it was eliminated? There are a couple things. One is people traveling from abroad bring it from different countries. In particular, people that travel from Israel, the Ukraine, or the Philippines have brought it over to the U.S. Then we have pockets of unvaccinated people, and that has spread the epidemic. And states which are currently experiencing an epidemic include New York, Michigan, New Jersey, California, Georgia, and Maryland.
About 90% of the individuals in the U.S. who have contracted measles have not been vaccinated, but 10% have. You say, “Isn’t it effective?” Well, it is effective if someone has received two doses. Most everybody that’s been vaccinated since 1989 has, in fact, received two doses of the vaccine. But prior to that — let’s say from 1957 on to 1989 — people either received an inactivated virus, which is not as effective, or only a single dose. People prior to 1957 just have natural immunity. So it’s recommended that if individuals are traveling to one of those countries I mentioned, they receive a second dose of the vaccine. Anybody vaccinated prior to 1989 and after 1957 should also receive a second dose and probably healthcare workers as well because of their vulnerability.
Elizabeth: I think it’s worth noting that titers are not necessarily predictive of whether adequate immunity exists, and so I don’t think people can short-circuit this by going to their physician and saying, “Hey, let’s take a blood test and see if I’m immune.”
Rick: You’re right, Elizabeth. Conversely, receiving a second dose of the vaccine is easy, it’s safe, and it’s relatively effective. We know that contracting measles can be dangerous. It can cause deafness, blindness, brain injury, and actually death as well.
Elizabeth: So for anybody in that cohort, it sounds like they’ve got to go out there and roll up their sleeves, huh?
Rick: That’s exactly what I’d recommend.
Elizabeth: Amen. Let’s turn from here to the journal [of] Radiology. This was a study taking a look at this technique that’s called tomosynthesis and regular old digital mammography with regard to screening. A previous study established that in younger women, tomosynthesis — this technique that sort of registers the images in a way that, to me, looks very reminiscent of a CT scan — was actually better in many respects than just regular old digital mammography.
But this was not examined in older patients, so this study is a retrospective study looking at screening mammograms in patients 65 years and older between March 2008 and February 2011. I think it’s interesting to note that nearly one-half of breast cancer-related deaths in the United States in 2017 occurred in women age 70 and older, so this is an important population to study. We know, also, that a woman’s risk of breast cancer increases as she ages, so understanding what is the best screening technique is really a good idea.
In this case, they compared digital mammography, 15,000+ folks with the tomosynthesis group, 20,000+, and they said, “What were the differences here?” There was no difference in the cancer detection rate, but the tomosynthesis group had a lower abnormal interpretation rate, higher positive-predicted value, higher specificity.
In that group, they also had a higher proportion of invasive cancers relative to in situ cancers and fewer node-positive cancers. So, in sum, then, it sounds like tomosynthesis is superior to digital mammography and should justify for insurance companies the increased cost relative to that technique.
Rick: I must say, though, when you look at the differences between the two, although they’re statistically different, clinically, there’s probably not a whole lot of difference because the differences were less than 1% sometimes, sometimes as small as 0.1%, and when you have 25,000 patients, statistically that’s significant, I would say that the most important thing is that women over the age of 65 realize that they need to undergo mammography.
Elizabeth: Your point is well taken with regard to the relatively small differences in all of these metrics except for higher positive predictive value, which was 14.5% versus just about 12%. I think if you factor in the really large populations that we’re considering here, those turn out to be pretty significant.
I think the other part that’s worth adding to what you recommended is that since people are living longer and they also oftentimes have fewer comorbidities or other medical conditions that might compromise their survival, this issue of breast cancer becomes even more important.
Rick: The American Cancer Society recommends that older women have biennial screening until it’s expected that their life expectancy is less than 10 years. Now the USPSTF says the evidence for women over the age of 75 is lacking, not that they don’t recommend it. They just suggest that, in fact, there’s not quite as much evidence, which is a little bit at odds with the American Cancer Society.
Elizabeth: Yeah, I thought that the difference between these different society recommendations was interesting, also. The authors, of course, in this study conclude that their study supports guidelines recommending that screening decisions be based on individual preferences and health status rather than age alone.
Rick: Absolutely. This is what is [known as] personalized medicine.
Elizabeth: Now, let’s turn to the journal Hypertension and [take] a look at, “Gosh, what happens when we lower blood pressure in patients with type 2 diabetes with regard to their cardiovascular risk?”
Rick: We know that having diabetes is a significant risk factor for developing cardiovascular disease. And in fact, the risk of future cardiovascular events is as significant as if someone’s already had a previous heart attack, so we want to try to prevent or minimize that. One of the ways to do that is to make sure that their blood pressure is under good control. Now there’s been some controversy about what blood pressure should be at which therapy is initiated.
These authors attempted to look at that by using a study that’s already been done. It’s an advanced study and they did a post hoc analysis. Now, by the way, the advanced study showed that if you lower blood pressure below 140, you decrease the risk of macrovascular and microvascular events. But what they ask is two things. One is, does it depend what your initial blood pressure is? Secondly, does it depend upon what your underlying cardiovascular disease risk is over the next 10 years?
And they had a large population, almost 11,000 patients in this study, and what they determined was that there was benefit regardless of whether your blood pressure was 140 or 130 and whether your cardiovascular risk was over 20% or less than 20%. So adults with diabetes appeared to receive benefit from more intensive blood pressure therapy even at levels of blood pressure and cardiovascular disease risk that some guidelines currently don’t recommend [that] therapy be initiated.
Elizabeth: And since we know that these folks are already at increased risk for cardiovascular disease, it seems like this is a really prudent idea even though it’s going to result in polypharmacy.
Rick: This was an unusual study in that it was a fixed-dose combination medicine — the combination of an ACE inhibitor and a thiazide-like diuretic. Most of the benefit here occurred in the range of 130 to 140 — that is, getting it below that. These individuals were often on multiple medications. Unfortunately, diabetes is a significant risk for stroke, heart attack, mortality, so getting all [of] these things under control is essential to lowering those risks.
Elizabeth: Let’s turn to the last one for this week and that’s in JAMA Network Open. This was a study taking a look at rehabilitation after total knee arthroplasty or knee replacement. And these were folks who had had just a single knee replaced. I’m always hearing all these stories from people about how they go in and they have both of them, so I thought it was interesting that they limited it to just the one knee. They were looking at, “Hey, what about rehabilitation? Does it matter if we give it as an inpatient or can we do it in a home-based program?” There’s some new data relative to this.
This was a meta-analysis where they took a look at five studies with 752 unique participants, the majority of whom were female, and they compared clinic and home-based rehabilitation. They concluded basically that there was low-quality evidence and I think that that’s significant. Sounds to me like they need to do a little bit more study on this, but this low-quality evidence showed no clinically important difference between clinic and home-based programs for mobility at 10 weeks and 52 weeks, and then there was moderate-quality evidence showing no clinically important difference between where you received your rehab for patient-reported pain and function at 10 weeks.
I thought it was also interesting they looked at, “How was this home-based rehabilitation delivered?” One thing that caught my eye was that some of it was via telemedicine, and we are certainly seeing way more delivery of all kinds of interventions via that method now. To me, it sounds like, gosh, you don’t have to stay in the hospital. You don’t have to be in a rehab facility. You can achieve this same outcome if you, I guess, take it seriously at home.
Rick: And this is an important message because total knee replacement is the most frequently performed inpatient operating room procedure in the United States. In fact, over the next 7 or 8 years, we’ll be doing 3.5 million of these. Oftentimes, the insurance company bundles the payment. They pay either the hospital or the health care providers or situation a lump sum for the first 90 days, the operation and the first 90 days of care.
Doing inpatient rehab or even doing it in the clinic-based situation is much more expensive than doing it on an outpatient basis. So knowing that there’s no difference in terms of patient outcomes, in terms of mobility or pain control, in outpatient versus inpatient or clinic, is really an important message.
Elizabeth: I would think it would be way less onerous for patients to have it delivered at home than it would be to have to remain in the hospital or rehab facility in order to have this. Then when I thought about that a little further, I thought, “Well, gosh, I guess there are probably some patients who are more motivated if they’re inpatients than if they’re at home.”
Rick: A couple caveats. These were all uncomplicated total knee replacements, and they all had adequate social support systems as well. But Elizabeth, your point is very well taken in that it’s much more convenient to do it at home, to do it on your own time, and for many people that are in a low socioeconomic situation, they can’t make it back and forth to the clinic or they can’t make it back and forth to the hospital to receive physical therapy. Knowing that it can be delivered at home and receive results that are just as good is important.
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.