Like many Americans, I recently watched You Can See Everything, the documentary that follows Elizabeth Holmes through the weeks before she reported to prison. I left the theater fascinated and bewildered. Throughout the movie, I kept asking the same question the filmmakers seem to be asking: Am I being deceived, or am I missing something because I don't know enough?
I have asked myself that question about Holmes before. In July 2013, I was the Deputy Commissioner for the New York City Health Department, where I oversaw the city's infectious disease programs and the public health laboratory. City Hall asked me to meet with a promising new lab-testing company; a few weeks later, I joined an hour-long video call with Holmes, her team, and our lab director.
I still have my notes. Holmes and her colleagues told us that their company, Theranos, had developed a more convenient way to test blood in small amounts that would cut testing costs by 30 percent.
They said:
A wide range of tests had been validated
Federal and New York State regulatory approvals were complete
They secured a Department of Defense contract.
Testing was scheduled to launch at New York Walgreens pharmacies within months.
My colleague and I asked repeatedly about the underlying science and data. Every time, we got the same answer: They could not disclose business secrets, but everything worked and was approved. Rest assured.
When the call ended, my colleague and I were dumbfounded. Nothing we knew about collecting specimens, validating tests, or getting regulatory approval made their story plausible. And yet I doubted myself. Holmes spoke with such composure and certainty and had such powerful connections and investors that I kept wondering: Did she know something about science or lab regulations that I didn't?
We offered to evaluate the device in our lab before any wider use. Neither side ever followed up. When the Wall Street Journal published its first investigation into the company in October 2015, I called my colleague, and we both said the same thing: "We knew it!" Most of what she said in that meeting was not true.
After watching the movie, I kept thinking about that incident and how it raised a hard healthcare problem: knowing when to trust your own expertise and when to defer to someone else's.
Confidence Is Not the Same as Competence
We assume that people who sound certain know more than we do. This is particularly common when checking a person’s claims is difficult or costly. That describes the Theranos meeting almost exactly. We could not check her claims because she said her data was confidential, and she spoke with absolute certainty.
While the lack of data made me suspicious, I fell prey to something known as “the halo effect,” where people with credibility in one domain are often thought to be credible experts in other domains. Theranos had funders and board members who had extremely prestigious backgrounds in government and the military. Even though none of them had a background in laboratory medicine, I assumed they had done sufficient due diligence on the technology.
Can You Be an Expert in Everything?
A big challenge in health: The body is so complex that none of us can be experts in everything. As a physician, if I order an MRI on a patient, I rely on the radiologist to interpret it correctly. When I order a blood test, I rely on laboratory technicians to use validated methods and equipment. I could not do my job if I had to personally verify that everyone knows what they are doing and is doing it correctly. The need to trust others is even greater for patients, because most of them will not be medical experts.
The problem, of course, is that humans are imperfect. Medical errors are, unfortunately, quite common. Someone did something wrong—errors of commission; someone forgot to do something—errors of omission. And, because medical knowledge is always growing, something correct 10 years ago may be incorrect now. I always encourage people to ask their healthcare providers questions and, with major health decisions, to seek second opinions.
How to Decide When to Trust a Health Expert
How do you decide when and whom to trust? Here are a few questions you can ask whether you are a patient talking to a doctor or interpreting health claims online.
First, is this an area where you have real knowledge and experience? If so, give your own judgment more weight than you are inclined to, even when the person across from you is more confident than you are.
Second, does their authority come from the relevant field? A famous name, a large social media following, or impressive business credentials do not mean they understand how a vaccine works or what a blood test measures.
Third, is the other person offering evidence or only certainty? Consider asking, “What is the evidence that supports this approach? Is this what expert guidelines recommend?” Trustworthy experts can explain their reasoning or point you to high-quality studies or published guidelines to check their claims.
Fourth, has anyone independently checked? Has it been approved by the FDA or another government regulatory agency? Or do major professional organizations recommend it?
We need our health experts and institutions to see everything—the methods and the data—to make sure medications, vaccines, and other health interventions are safe and effective. But when someone asks for our trust and won’t back it up with data, we need to consider trusting our own judgment or asking for a second opinion.