Beck: When people are seeking out these alternative medicines or diagnoses, with people who think their chronic fatigue is caused by Lyme disease, or anti-vaxers, things like that, how much of that comes from the fact that science isn't able to offer them much certainty at all, whereas the false explanations can?
Hatch: I think that is the central explanation for their appeal. What they offer that we don’t is the comfort of certainty. And I wish I could say that the story ends there. But I think the other thing that they offer that mainstream medicine often fails to deliver in those situations is sympathy, understanding. When I see patients in the Lyme-disease clinic who are these chronic-fatigue patients, the first message I give isn’t about Lyme disease, it’s, “I believe you and I hear you.”
The other thing I often try to tell my patients is, “I don’t think you’re crazy.” Because a lot of times, they go to doctors and the doctors don't know what's going on, and they eventually get the message, either literally or nonverbally: “Not only do they not believe me, but they think I’m just totally insane.”
Beck: In the context of testing, we end up with a lot more false positives than false negatives, and the scale skews toward overdiagnosis rather than underdiagnosis. Why is that? Why do we run in that direction?
Hatch: Some of it is, we're really hardwired to react more to positive tests. There’s this sense that doing more is better. It seems logical. What we’ve found just by looking at data and doing studies, is that more doesn't always equal better and more can often lead to harmful outcomes. It’s an assumption shared by both patients and doctors that you should always do more testing because it shows you that you’re doing something. One of the messages I was hoping to get out in the book is that you can flip the old statement on its head. Don’t just do something, stand there. Let's slow down and let's think about what the implications of the testing that we're doing are. The more tests you do, the more likely you are to find some result and then feel compelled to act on that result.
Beck: I think that's been starting to switch a lot recently, especially in the realm of women's health. It seems like the recommendation is don't do anything anymore. Fewer mammograms, fewer pap smears, don't do self-breast exams, all these things. Can we talk a little more about this famous example of mammography? How did a misunderstanding of uncertainty lead to too much screening and the overdiagnosis of breast cancer?
Hatch: Boy, that's a big question. The first trial started in the mid-‘60s. By the mid ‘70s they’d accumulated data, and what the data showed was that there was about a 33 percent, one-third reduction in the number of deaths from breast cancer [with screening mammograms]. And you say, “Wow, one-third reduction is huge!” In reality what the reduction was, was there were 128 deaths in the group that didn’t get mammograms, and 91 in the women who did, but the overall number of each group was 31,000. What you realize is, you’re squinting. It turns out the number can be portrayed in two different ways. One is the relative reduction, which is 128 versus 91, that turns out to be 33 percent. Or the absolute reduction which is 91 over 31,000 versus 128 over 31,000, and that comes out to be one-tenth of 1 percent. So you actually have a very, very small absolute benefit to mammograms. Neither number is lying. They’re both accurate descriptions. But obviously, they have very different emotional impacts.