The Doctor Has No Clothes

By Dr. Michael Couturie

My office shares a wall with a pediatrician’s office, so the sound of crying coming from my left is pretty routine. This time, though, the tears were coming from the obstetrician’s office. I assumed a miscarriage, but five minutes later the obstetrician slammed a 13-page report on my desk, and I realized it was another case of a peculiar epidemic in my practice – health-check scares.

The patient was a young woman who works at a foreign company in Beijing. Her company offers their employees an annual health check. She doesn’t speak Chinese well, but the health-check center seemed clean and modern, the services were efficient, and the report helpfully translated into English. They even had a mobile app. She had believed she was healthy, but the health check found eight major health issues, including a congenital malformation of her uterus that she was told would make getting pregnant and having a baby difficult, if not impossible.

The only problem was that her uterus is completely normal. As are the seven other medical “problems” the health check reported. This perfectly healthy woman took advantage of her company’s well-intentioned benefit and was directly harmed as a result. The simplest explanation might have been that the health-check center was incompetent. The reality, though, was that this is a predictable, well-known, and well-documented consequence of annual health checks and the gross overuse of medical testing they entail.

Origins and Evidence

Why do we even think we need an annual health check? It’s unclear how, exactly, the belief started, but a rough timeline has been traced.^[1] Dr. George Gould, a prominent US physician in the late 19th century, generally receives credit for first proposing something akin to the annual physical exam,^[2] but it was not until 1922 when the American Medical Association officially endorsed the idea^[3]. The concept was generally ignored, though, until the late 1940s when effective treatments for tuberculosis became available, and thus the value of screening for the disease became clearer. As tuberculosis decreased in the US, screening for other conditions began to be considered. Concurrently, the development of “multi-phasic screening” – basically, packages of lab tests – allowed organizations to offer screening with minimal physician involvement. Employers in the US got involved in the post-World War II period when health benefits became a tool for attracting and retaining staff. Over time, the annual health exam became part of the normal health insurance benefit provided to employees.

Unfortunately, enthusiasm for annual health checks outpaced the evidence – a situation lamentably common in medicine. Kaiser Permamente Health Plan in California, in particular, led the development of multi-phasic screening. However, to their credit, they were also one of the first to study these tests’ effectiveness at helping people live longer or without disease. In 1973 they published data on 10,000 people randomized into 2 groups – one screened, the other not. There was no difference between the groups’ death rates, disease incidence, physician visits or hospitalizations.^[4],[5] Similar studies followed from the US^[6], Sweden^[7], England^[8] and Japan^[9]. More recently, the Annals of Internal Medicine published a systematic review in 2007 and concluded health checks provided no benefit^[10]. In 2012, the Cochrane Group published their own review in the British Medical Journal, again showing no health or mortality benefit^[11]. They also highlighted the important missing data regarding the harms of over-diagnosis and overtreatment.

It takes about 17 years for research evidence to become standard medical practice^[12], so depending on when you start counting, we are either very early or very late to expect changes. Either way, changes are coming. In the US, the Society for General Internal Medicine recommends against the annual health check.^[13] The British Medical Journal^[14],[15], Journal of the American Medical Association^[16], New England Journal of Medicine^[17] and other professional medical societies and journals have all called for this practice to stop. In the press, the New York Times^[18], The Globe and Mail^[19], The Guardian^[20], Harvard Business Review^[21], Salon^[22], Slate^[23], and even HR Magazine^[24] have published articles arguing against annual health exams. (In this regard, Canada is well ahead of the game – in 1979, the Canadian Task Force on the Periodic Health Examination recommended “that the annual checkup, as practiced almost ritualistically for several decades in North America, be abandoned.”^[25]) And lest anyone think this is solely a Western phenomenon, the Vice Chairman of the Chinese People’s Political Consultative Conference National Committee and Chairman of the Chinese Association for Science and Technology has spoken out against universal cancer screening specifically because of the risks of over-diagnosis and harms.^[26]

Magical Testing and Broken Clocks

Of course, what this young woman experienced is different from what most US patients expect in an annual exam. Even the fiercest annual health exam proponents argue that their value lies in the patient-physician relationship, not the testing.^[27] The approach in Asia seems to be the opposite: ultrasounds of the entire body, blood tests for tumor markers, stress tests, bone density scans, mammograms, CT scans, MRIs – all done solely based on ability to pay and with little regard to effectiveness or appropriateness. Most centers offer tiered packages, such as basic, standard, comprehensive, and maybe even a VIP or Executive package, with increasing quantity of tests as you pay more. The marketing for these packages is easy: “Make sure you’re healthy,” “Catch disease early,” and “Peace of mind.” “Early detection saves lives” is a magical incantation that renders people incapable of even asking whether the tests work for early detection, much less whether early detection really does save lives.

Part of the confusion stems from a belief that medical testing is like testing a car engine – open the hood, check the oil, and add some more. That is not how medical testing works. Most medical tests – including and especially blood tests – must be interpreted within the context of disease probability, something most of us – doctors included – are simply not good at doing, if we even do it at all.

Here’s an example. Let’s say a person has a 1 in 1000 (.1%) baseline chance of having a disease – something we can roughly gauge based on disease prevalence rates. Now let’s say we have a blood test to look for this disease that is 90% sensitive and 90% specific^[28] (which is a very good test). The blood test comes back positive. What is the chance the patient has this disease? When Harvard Medical School students were asked this question, they guessed the chances were about 90%. In fact, the probability is slightly less than 1%, which means there is a greater than 99% chance the patient does NOT have the disease, despite the positive test result. The math is a straightforward application of probability, but most of us are simply not good at thinking this way.

Bayes' Theorem explains how a positive result doesn't mean you are sick.

If the issue was simply people paying for useless tests, “caveat emptor” would sufficiently rebut most concerns. But false-positive and false-negative results from preventative testing have truly negative consequences. This is why the United States Preventive Services Task Force, a group specifically tasked with evaluating preventive medicine approaches (and explicitly forbidden by law from considering cost-effectiveness), actively recommends against screening for prostate cancer with the PSA test – the test harms more men than it helps.

Another source of confusion is a lack of understanding regarding how diseases develop. Some diseases take decades to become clinically relevant and some diseases develop extremely rapidly. And sometimes diseases never even become clinically relevant at all, meaning that the disease has no tangible or negative effect on a patient’s life or lifespan.

Thyroid cancer is a very good example of this, and is developing into the quintessential example of over-diagnosis. After screening thyroid ultrasounds were introduced in South Korea, Japan, the US, and elsewhere, thyroid cancer diagnosis rates climbed rapidly. This makes some sense, as one would expect to find more cancer when you look for it. But despite finding more and more cancer, and treating those cancers with surgery and radiation, the overall mortality rate – the number of people who die from thyroid cancer – has not changed. This means that people are being diagnosed with and treated for a “cancer” that never would have had any negative impact on their lives. By one estimate, screening has led to half a million people receiving unnecessary treatments for thyroid cancer.^[29] This is worse than making healthy people worry unnecessarily: We have removed peoples’ thyroid glands and put them on lifelong medication for a condition that would have never caused them a single clinical problem.

Of course, if you test enough people, eventually you will find a clinically relevant cancer, and people selling health checks all have a story to tell about a patient saved from cancer, or a heart attack, or a stroke because of a health check. But these stories are not good evidence of effectiveness, and doctors and health check center staff should know this. There is no mention of lead time bias, ascertainment bias, vividness bias – all of the ways in which our brains are fooled into believing something false is actually true. And the marketing brochures certainly don’t mention all the false-positive AND false-negative results.  It’s easy to forget that these tests miss a lot of people who actually do have disease, especially cancer.  A broken clock is only accurate twice a day, so relying on it to tell time will consistently and predictably cause problems, no matter how much you pay for the clock. Pretending these so-called comprehensive health checks with their long lists of tests help people live longer or healthier lives is irrational, misleads people about health and wellness, and ultimately betrays the trust people should have in the healthcare system.

Don’t mistake this for cynicism or diagnostic nihilism, though. If a patient has symptoms of a disease, doctors use tests to diagnose and monitor that disease. Screening tests, by definition, are done in asymptomatic people without signs or symptoms of the disease being screened for. Also, some tests have been shown to be useful for disease detection and prevention in certain populations. Cardiovascular risk stratification, colon cancer screening, cervical cancer screening, gastric cancer screening – there is good evidence for these in selected populations. There may come a time when we actually can screen effectively for more diseases, including more types of cancer. But that time is not yet here, and if and when people claim otherwise, they will need to prove it, just like anything else in healthcare. Medicine may be a science and an art, but it is not a religion – we don’t get to take things on faith.

"If a patient asks a medical practitioner for help, the doctor does the best he can. He is not responsible for defects in medical knowledge. If, however, the practitioner initiates screening procedures he is in a very different situation. He should, in our view, have conclusive evidence that screening can alter the natural history of disease in a significant proportion of those screened." Cochrane A, Holland W, Validation of Screening Procedures, British Medical Journal, 1971; Vol 27 No. 1.

People don’t want to buy a quarter-inch drill; they want a quarter-inch hole.^[30]

Multivitamins’ continued popularity despite abundant evidence that they do not prevent disease or help people live longer^[31] shows that convincing people to stop believing something is hard – especially when that something has a large marketing budget. Nevertheless, I am baffled by companies’ continued insistence on paying for this. Obviously companies must comply with occupational health regulations, but if I approached an IT manager and offered to sell her virus-scanning software that would take her computers offline for a day, misidentify files as a virus more often than finding an actual virus, and then require follow-up testing at additional time and monetary costs to clarify, I would be quickly shown the door.

However it started, companies have been providing employees this “benefit” for years, so now we have a whole health check industry – not just in China, but internationally. As of 2014, there were approximately 8,000 health check centers in China – nearly 300 in Beijing alone – and industry experts expect this number to grow.^[32] HR managers have a budget per person for health checks, and health check providers compete by doing more and more tests in fancier buildings. HR managers aren’t trained to evaluate medical test performance, so how else can they judge value? Health check providers don’t want to lose business because their list is shorter. Caught in the middle are the employees and their families who now think more testing means a better product. Even people without MBAs should recognize that people don’t want health check packages because they want a specific combination of tests. People want to live long and healthy lives, and they have been misled to believe these tests will help them do that. It’s not their fault they have been misinformed.

Unfortunately, I am not optimistic that change will come from providers. As the British Medical Journal writes: “The history of health promotion through routine health checks has been one of glorious failure, but generations of well-meaning clinicians and public health physicians struggle to allow themselves to believe it.”^[33] While the US market is moving away from a fee-for-service, volume-based healthcare market to one that rewards value, much of the private healthcare market still incentivizes excess and waste. But with healthcare expenses eating more and more of corporate budgets, some employers are pushing back. Intel and Walmart have partnered with healthcare centers and insurance companies in the US to redesign care processes, including health checks, to focus on providing evidence-based care, at significant savings.^[34]

And some providers are trying, too. In my clinic, we are developing a longitudinal wellness program. The principle is to use frequent contact and nudges to help people achieve health and wellness goals selected after a personalized, rational, evidence-based evaluation – one that doesn’t expose employees to low value and potentially harmful testing. We want to partner with our corporate clients to actually improve their employees’ health. But we are still in the design stage, and as my marketing colleague frequently reminds me, the market still wants these packages. How does an organization committed to high quality, high value, evidence-based care convince their clients to move away from “the way we have always done it” without losing their business? Still, the future seems clear: no organization can or should continue buying services that don’t actually add value, and healthcare services should not be exempt. It’s far past time for organizations to start asking what they are buying, and why they are buying it.

In my office, though, I deal with real people, not corporations, and it’s getting harder and harder to wait for organizations to stop exposing their employees to these unnecessary risks and for health check providers to stop misleading people about health and disease. For the fictional citizens of Hans Christian Anderson’s tale about the eponymous Emperor’s new clothes, a bit of embarrassment was the only side effect to their self-delusion about his finely tailored garments. But the Emperor truly has no clothes, and the consequences of this particular pluralistic ignorance are far more serious than wasted time, effort, and money. The young woman who saw my colleague was lucky enough to access a specialist relatively quickly and, aside from a week or so of unnecessary anxiety, was not seriously harmed. How many people are not so lucky?

Dr. Michael Couturie, an American Board of Internal Medicine Certified Specialist in Internal Medicine practicing in China.

Below is a table of important, evidence-supported medical tests, including guidelines about who should get screened and at what age.