Live Long and Well with Dr. Bobby

Episode 12: To Test or Not To Test?

• Dr. Bobby Dubois • Season 1 • Episode 12

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We’re bombarded with advertisements for all sorts of tests these days: comprehensive blood panels for a few hundred dollars, total body MRI scans for cancer detection, heart calcium scans, and even tests to rule out multiple cancers. But are these tests worth it if you are asymptomatic and don’t have an important family history? 

A few years ago, I experienced fainting episodes while running. After a series of tests, including seeing a cardiologist, I was told that my blood pressure dropped upon standing—a condition that required no treatment, just caution. During these tests, they found that my heart was larger than usual. This discovery led to a lot of anxiety over the years, despite it likely being a false positive. This case illustrates how even with legitimate symptoms, testing can sometimes lead to more questions than answers.  And, large panels of tests compound the problem.

The Issues with Testing

It’s tempting to think that more testing is better, but the reality is that tests are imperfect. They’re often based on statistical averages, and results can be misleading. For example, if you undergo multiple tests, you’re likely to get some abnormal results just by chance. This can lead to further testing, expense, time, potential medical complications, and unnecessary worry.

Medical Expert Recommendations

Organizations like the US Preventive Services Task Force and the American College of Radiology provide guidance on screening tests. They recommend specific tests like pap smears, mammograms, and colonoscopies, but not routine total body MRIs or large blood panels. Even well-regarded screening tests can result in false positives, as shown by studies and practices in countries like South Korea.

Real-Life Examples

I’ve seen friends go through the stress of false positives from MRIs or calcium scores, leading to further tests and anxiety. It’s essential to weigh the potential impact of these findings on your life, including how they might affect insurance and your mental well-being.

Conclusion

To sum up, while early detection of health issues sounds appealing, the reality is that many screening tests can lead to false positives and unnecessary complications. If you’re asymptomatic and don’t have a concerning family history, it’s often best to save your money and avoid these tests. Always consult with your doctor to make informed decisions based on your specific health needs.

Dr. Bobby Dubois:

Hi, I'm Dr Bobby Dub ois and welcome to Live Long and Well, a podcast where we will talk about what you can do to live as long as possible and with as much energy and vigor that you wish. Together, we will explore what practical and evidence-supported steps you can take. Come join me on this very important journey and I hope that you feel empowered along the way. I'm honored to be your guide. Hello everyone, and welcome to episode 12. To test or not to test? That is the question, and in this episode we are going to explore the pros and cons of undergoing a panel of tests when you're asymptomatic. Now, this is an important topic because there are so many opportunities to get testing done and many companies are marketing directly to consumers, so your doctor is typically not involved. You see advertisements for doing hundreds of blood tests for $500 or so, or a total body MRI scan for $2,500 to find cancer, or perhaps a brain aneurysm, or perhaps a heart calcium scan for a few hundred dollars to see if you have heart disease, and finally a blood test to rule out 50 cancers for a thousand dollars. Are these tests a good or bad idea for you? Ultimately, of course, you should talk with your doctor, but I hope by listening you'll be a wiser consumer and can better decide what might be appropriate for you. I generally don't support these types of screening tests when you have no symptoms or if you don't have a particularly worrisome family history. Well, before we dive in, let's summarize our take-home messages, as we always do. First take-home message there are good theoretical reasons why people might consider these blood panels or MRI scans. Look, we all want to remain healthy and it seems like a good idea that finding a problem early would be helpful. Second take-home message if all tests were perfect and an abnormal result meant something important was going on, then that would be great. But blood tests and scans aren't perfect and although they may identify an issue, and although they may identify an issue, it may turn out to be something that was not of real concern and we call these false positives and they can lead us to significant expenses, stress and harmful medical complications. Much, much more about this later, because this is the heart of the issue. About this later, because this is the heart of the issue. Now. Testing when you have symptoms or you have a strong family history is a whole different story. It's not the topic for today and, of course, testing in that situation is very appropriate. Fourth take-home message armed with this understanding, I hope you will have a better position to decide what's best for you and, as I said earlier, in general I would save your money not do these screening tests and hopefully avoid the avoidable problems that can result from them. That's where we're heading Now.

Dr. Bobby Dubois:

How are we going to get there? Our roadmap Part one we will start with some background information and once again, I'll begin with a case study, and this is once again a case study about what happened to me. Next, we will briefly review some concepts like how tests determine what is positive and negative and what a false positive actually means, and this is central to the discussion. The third part we will review what types of screening tests are supported by medical society and which ones, frankly, are not. Fourth provide a framework for how you might begin to think through the pros and cons of the decision and end with what type of testing I think might be helpful. All right, so that's the take-home messages and that's the roadmap for today. So let's dive right on in the case study.

Dr. Bobby Dubois:

Well, a bunch of years ago, while I was running, I fainted, and this happened a couple of different times while running, or, more specifically, I would come to a red light, stop and then wake up on the ground looking up. At first I tried to ignore this, but I finally decided it was time to go to my doctor. I got a whole bunch of tests done, ultimately was sent to the cardiologist and he found that my blood pressure fell when I stood still and he found that there's no treatment needed. I just had to be more careful and if I came to a sudden stop I had to be careful and sit down if needed. Now that all sounds good.

Dr. Bobby Dubois:

Sounds like I had a problem. I got some testing. We figured it all out, but during the course of these tests, they found on one of the studies my heart was large. Well, not because I'm such a loving person, but it was actually larger in my chest than normal, of course. I then turned to the cardiologist and said why is this? He says well, I don't know, but as an athlete, this sometimes happens. I then asked of course, is this a problem? He said I don't really know. I then asked will it go back to normal if I stopped exercising as much? And he said hmm, I don't really know. I then asked will it go back to normal if I stopped exercising as much? And he said hmm, I don't know.

Dr. Bobby Dubois:

Well, while I was sitting in the office and not getting direct answers to some of these questions, I saw a textbook on his shelf that was titled Sudden Death in Athletes. Well, as an athlete now told, I have a large heart. This wasn't very reassuring to me. Okay, so for the next several decades I lived knowing that my heart was larger than usual and didn't know if it was actually a problem or not. Well, the good news is that I've survived for several decades with this, and I'm guessing that the large heart finding was a false positive, and I point this out, that it wasn't a screening test that I might not have done. It made sense because I had the symptom of fainting, but I still ended up finding something that worried me over the years that there wasn't anything to do about and was probably a false positive. So that's a case study. We're going to come back to these issues and hopefully, by the end of the podcast, you'll have a really good sense of the pros and cons of thinking about this.

Dr. Bobby Dubois:

Okay, so doing one of the panel tests for a total body MRI or the large group of blood studies seems like a good idea. We all want to be healthy and testing seems obvious. We should do it, and the more we know about our body the better. That just seems logical. And as the marketing for all these things talk about, finding an illness early seems great. Yeah, if you could find cancer when it's small, that could allow us to cure it perhaps. But just like me with my testing, you're very likely to find something in these studies that might lead to worry and further care, which may not be necessary. Now, to understand how this happens and why it's so important, we got to move on to part two of the podcast, and to do that we have to get a little bit nerdy. I'll try to keep us from getting too nerdy, but we do have to talk about tests and how they're designed and how they determine positive and negative. So two concerns, and I'll try to keep this at a high level so that folks don't go to sleep and don't get confused.

Dr. Bobby Dubois:

For many tests think about blood tests there's no gold standard or absolute. Now you might think there is. You might say, oh, my sodium is low. Well, that's an absolute problem. Let's twist this a little bit. What if I said to you what's the normal number of freckles on your body or the normal number of hair follicles on your head? This is just like blood tests, where positive is based upon a statistic which is two standard deviations from the mean, or simply put the top 5% or the bottom 5%. So, arbitrarily, we're going to say how many freckles a person has and if you're in the top 5% of freckles, we're going to say that's abnormal or positive. Similarly, if you are in the top 5%, even if you have no symptoms, even if you have no problem with your sodium or other blood tests, by definition 5% of those folks are going to be termed abnormal Too many freckles, too few hair follicles or an abnormal sodium or calcium, too few hair follicles or an abnormal sodium or calcium. That's what happens. It's statistical. So what is the practical impact of this? If you were to do 20 blood tests and each one has a 5% chance of being positive, just arbitrarily, if you did 20 of them, at least one is going to be abnormal. If you did 100 tests, five of them likely would be abnormal. If you did 300 blood tests, it might be 15. So, almost inevitably, if you do a large panel of these testing, you're going to have abnormalities. Now the trick is knowing whether to worry about each of these abnormalities, and it's not a simple determination to say, oh, don't worry about these three, but these three you probably should worry about. And thus the problem of the false positives.

Dr. Bobby Dubois:

There's a second issue with testing that's important to understand. Tests aren't perfect. They have inaccuracies. So let's take an exercise stress test where you run on a treadmill. They measure your EKG, your blood pressure, your heart rate, various other things. A positive or negative result might well hint that something's going on, but it won't tell you for sure. And there are terms you'll run across, like sensitivity of a test or specificity, and I'll briefly mention them so you can understand. Sensitivity means what's the likelihood that, for example, an exercise stress test will pick up blocked arteries or partially blocked arteries in your heart.

Dr. Bobby Dubois:

So let's say we have 100 people and we know somehow or other that they actually in fact have somewhat blocked arteries. Would a treadmill test, all 100 of those people be positive? The answer is no, because the test isn't perfect. Perhaps maybe 70 or 75 of the 100 would show positive, but there might be 25 of them that we know actually has some blockage and the test wouldn't show it. So the test missed people.

Dr. Bobby Dubois:

So a blood panel might show a false positive. It also could show what we call a false negative. Specificity is, let's say, I took a hundred people that I know absolutely don't have heart disease and I run them on a treadmill test. You would hope that all 100 of those people would come back as normal or negative, but in fact 75% might come back as normal and there could be as many as 20 or 25 of that 100 people that might be labeled as abnormal or positive, even though we know, because we've done some other tests, that they don't have heart disease, because we've done some other tests, that they don't have heart disease. So in the course of my various workups, I've had an exercise stress test and it was very abnormal and that turned out to be a false positive. So if you do a large panel of screening tests, you are likely to have some abnormal results based upon statistics alone. But what does it mean? And that's where it gets difficult. Now, if you haven't already grasped the false positive problem, let me give you a completely non-medical way to think about this that we've probably all experienced Credit cards and fraud detection.

Dr. Bobby Dubois:

So you go into the clothing store and you try to buy some clothes and your credit card is denied. Or you're sitting at dinner and you get an alert that says they think your credit card company thinks that there's fraudulent activity on your card. Now that's the credit card company running a computer algorithm that looks at your purchases, looks at whether these purchases were in different cities, maybe different price amounts, purchasing of products that you wouldn't normally buy and there's then an algorithm that says, uh-oh, this could be fraud and they send you a text message or they send you an email message from your credit card company or they deny the purchase for you. If you're actually trying to buy something, 90% of these are false positive, as you know. I mean, you're trying to buy something, it's you, it's your credit card, you know it's correct. Or you talk to the credit card company and you say, oh, yeah, yeah, that was that Apple purchase that I made last night.

Dr. Bobby Dubois:

So nine times out of 10, a positive is actually a false positive. And of course, there's the other side of it. They do actually miss real cases of fraud. Those would be called false negatives. So the fraud test isn't perfect. It misses cases and it gives you alerts that are probably not correct. Now, if it's a credit alert, no big deal, you're sitting at dinner, it takes a moment or two to respond to the credit card company, it's resolved. You go on with your dinner, no problem.

Dr. Bobby Dubois:

But if this happens with a blood test, a screening blood test or a total body MRI, and you get an abnormality, there isn't a simple way to say whether you can ignore it or it's the real deal. And so what happens is you do these screening tests, you get a positive, and now to figure out whether it's a real positive or a false positive, you got to go to a doctor. You have to have more testing likely. You may get a biopsy. There could be surgical removal, just like what happened with me with a large heart. The large heart turned out not to be a big deal, but there was a lot of testing that was done around the large heart and anxiety that I had over the course of a couple of decades. Now I don't want to drown you with examples, but I think each one of them gives us a little bit of instruction on how it might be helpful.

Dr. Bobby Dubois:

So a friend of mine had an MRI scan of his abdomen recently because he was having some not obvious symptoms, but some vague discomfort in his belly. Now the MRI scan good news didn't find any cause for his discomfort. But the problem is that while they were doing the scan they picked up a nodule in his liver and a small kidney stone. Well, now we've got these two positive findings. What should be done? Do you ignore them? Do you then have to go to the doctor, have more tests to do? And now he's just at the beginning of trying to figure out what is he going to do with this information.

Dr. Bobby Dubois:

At the beginning of trying to figure out what is he going to do with this information, another friend decided he was going to get a cardiac calcium score. It came back positive and he then had to have a whole series of tests over several months and was very anxious about it, and in the end he was already doing everything he could do. He was doing his exercise, he was doing the self-care, he had a good diet, and so what ended up happening is he added anxiety to his life, but not much information. That was very helpful. So for my friends that I've just talked about, getting the positive test result and working through the healthcare system to figure out what to do ended up costing the money, time and produced anxiety.

Dr. Bobby Dubois:

But there's another downside and this is something to keep in mind the friend that found the nodule or the positive treadmill test or the high calcium score in the heart, it may affect your ability to get insurance. So when you fill out the application for life insurance or disability insurance or long-term care, they're going to ask you about what studies you've had and whether there were anything positive. And because you did these studies and now you found that oh, by the way, I have a nodule here, I have a kidney stone there they're not going to necessarily care that you say, well, I'm not having any symptoms from that, I think I'm fine. It could affect whether you get insurance or what they charge you for it. So that's just another downside to testing when it's in an asymptomatic person. Okay, so let's now move to part three. You've heard my view, my way of beginning to think about it.

Dr. Bobby Dubois:

But what do some of the experts say? And, as always, I will put links in the show notes for all the things that I refer to. So the CDC has a task force called the US Preventive Services Task Force and they summarize evidence on screening tests and figure out what should be recommended for the population at large. The only screening tests they support, where they think there's evidence that it really can help people, are pap smears, mammograms, colonoscopy and lung cancer screening only for folks who have been smokers. They don't recommend routine PSA testing for prostate cancer or ovarian cancer screening.

Dr. Bobby Dubois:

So an interesting study asked the question well, if you didn't do the total body MRI scan or you didn't do these large blood panels, but you just did what the Preventive Services Task Force suggested, which are the things I just mentioned and what most of us try to focus on, even by doing just those, there was an 85% chance that you would end up at some point in your life with a false positive for one of those tests if you were a woman, and about 39% chance of a false positive in men. The reason the women are higher is they're getting the pap smears and the mammograms, and those aren't perfect as well. They often come up with hmm, there's something there. I think some further testing is needed. Another medical group, the US Endocrine Society, says vitamin D screening there's not evidence to support routine screening. Again, these are all in people who are asymptomatic. I'm not talking about people who have specific symptoms or your father died of a particular illness. This is just these routine screening when nothing is apparently wrong scan. The American College of Radiology, which is the premier organization in the radiologic community, says there's no evidence to support routine screening, total body MRI screening.

Dr. Bobby Dubois:

Again, if you don't have a family history and you don't have symptoms. And now you may be scratching your head, you're saying but wait a second, dr Bobby, isn't finding a cancer early a good thing? And on the surface it seems like of course it's a good thing. But it's actually more complicated when you think about cancer and you think about an MRI scan might identify a cancer. There's actually three different ways to think about those cancers. The first is yes, they found a cancer on the scan, good news. Well, frankly, it's bad news because this cancer example it's already spread, so it's too late to cure it and you haven't accomplished much by finding it a week or a month before you were going to have symptoms anyways, because it's already gone beyond the simple cure stage. So that's one type of scenario that an MRI scan might show something.

Dr. Bobby Dubois:

The second example, or second type, is a really, really slow-growing cancer that will never hurt you, for example, a thyroid cancer in many cases is not going to kill you. It's not going to cause problems. Prostate cancer they say that if you live long enough, every man will have prostate cancer. So most everyone dies with it, not due to it. So you may do a scan and the scan company might say look, we found your cancer. But again, this is a cancer that's not really going to have hurt you and therefore finding it doesn't do you all that much good. The third scenario, of course, is the one we care about, which is a really bad cancer, but you caught it really early and therefore at a stage where you might be able to cure it. The problem is that when you do all these MRI scans you're generally not going to find this scenario because it's pretty uncommon. You're much more likely to get the first one or the second one that you then have to chase after and figure out what to do. All right, let me give you a real live example here, because this kind of sounds theoretical.

Dr. Bobby Dubois:

In the 1990s, doctors in South Korea decided that thyroid cancer was a big deal and they had an ultrasound which was inexpensive, relatively speaking, didn't cause radiation, and they decided they were going to really use it a lot and try to solve thyroid cancer in South Korea. Well, what happened next was they had an epidemic of thyroid cancer. So between 1999 and about 10 years later, there was a six-fold increase in finding of thyroid cancers. But when they then looked at the cancer mortality, it didn't change. So what ended up happening is you found all these supposed cancers that weren't really going to hurt somebody anyways, and all of these patients then who had a cancer might have to have a biopsy, they might have to have unnecessary surgery, they might get complications from it. So just because theoretically, finding something early seems like the right thing, unless you've got the evidence to support it, makes a real difference, you've got to wonder.

Dr. Bobby Dubois:

Now, in the US now there's a huge amount of excitement about the grail blood testing to detect cancer, what they're calling a liquid biopsy. You just look at the blood and it tells you whether you have a cancer. At this point there are no outcome studies to say that people who do this testing will live longer or better than those that don't. Yes, it definitely may find cancers. But again, remember we talked about there's the three different scenarios the scenario where it's too late, the scenario where it's never really going to hurt you and then, of course, the one we care about. So I hope I haven't confused you too much, but where do we go from here? Where we go from here is we're back to the take-home messages, which is first.

Dr. Bobby Dubois:

There are really good reasons theoretically why people consider these blood panels or MRI scans, and we all want to remain healthy and it seems like a great idea to find a problem early. But, as we've discussed, all tests are imperfect, and if all tests were perfect then that would be great. But they're not and a test may identify an issue which turns out really not to be a concern. But during the course of figuring out if it's a false positive or a real thing, you're ending up going to the doctor, maybe with more expenses, more stress and maybe having complications that you really would prefer to avoid. Again, testing when you have symptoms or you have a strong family history is a really different story and these tests can be really really appropriate. So, in general, talk to your doctor, but if you don't have symptoms and you just want to know more about your body, in my opinion I would save your money not do the testing and hopefully avoid the false positive problems that we've talked about that can result from that.

Dr. Bobby Dubois:

Well, thanks again for joining me. If you have comments or suggestions for topics, please go to my website or Instagram, which are DrBobbyLiveLongAndWell, and until next time, I am honored to be your guide on the journey to live long and well. Thanks so much for listening to Live Long and Well with Dr Bobby. If you want to continue this journey or want to receive my newsletter on practical and scientific ways to improve your health and longevity, please visit me at drbobbylivelongandwellcom. That's drbobbylivelongandwellcom.