"What To Think About Conflicting Medical Guidelines"

RACHEL MARTIN, HOST:

Medical researchers are in a constant search for truth. Each study is supposed to be another step toward that goal. But it's pretty obvious that many studies just don't hold up. Think about the contradictory advice about what you should eat or drink. Coffee is bad for you, then it's good for you. Same goes for soy, even eggs, which have been in and out of favor. Scott Hensley, host of NPR's Shots blog, joins us to talk about the year in health and medical research and what lies ahead. Hey, Scott, thanks for coming in.

SCOTT HENSLEY, BYLINE: You bet.

MARTIN: So how can all of us make sense of all these conflicting health guidelines?

HENSLEY: Well, in the short run, be skeptical. It turns out that so much of this research that gets done, even the researchers' medical colleagues can't reproduce the results. And so what you hear today may be contradicted tomorrow. What I would say, though, is that in the long run, science tends to work it out.

MARTIN: Is this just something that's part of science and medical research? Or is something new happening?

HENSLEY: It is part of research. And I think what's new is that there's more acknowledgment within the field that the reproducibility of research is a problem. And it's something that people are specifically trying to address. And so in the case of the food studies, for instance, some of the scientific critics are calling out the methods. So studies that rely purely on questionnaires, for instance, have been seen as not as reliable as other kinds of studies that randomly assign people to have this diet or that diet.

MARTIN: Another area that seems to be marked by confusion is cancer screening. We've seen a lot of this, especially in the last year.

HENSLEY: Yeah, the American Cancer Society - very influential - changed the time at which women should think about starting mammograms. They had been saying 40 for women with average risk and moving that up to 45. That's a little closer to what some other groups are recommending. There's a federal task force recommendation that says for the average woman, it should be 50. But it's still confusing. How do you decide what to do and then how often to have the mammograms once you start?

MARTIN: So how do you decide? Does this mean we're supposed to just put a lot of faith into our general care practitioner?

HENSLEY: I think that's right. I mean, I think it's important to say here that these groups that are making recommendations are generally looking at the same studies. A lot of it is how do you make the trade-offs between the benefits and the risks of doing something versus not doing it? For instance, in the case of screening, it is a fact that with screening, there are many false alarms. And those can lead to unnecessary treatment, stress and worry. And they wouldn't have prevented an illness anyway. But you have to weigh that against the benefit, which is for those cancers that are caught early, it can really help treatment a lot.

MARTIN: And this came up in the world of statins, too. Can you tell us what happened there?

HENSLEY: Sure. So guidelines from 2013 could double the number of Americans who would be candidates for statins, these cholesterol-lowering drugs; think Lipitor.

MARTIN: OK.

HENSLEY: They showed that in fact, more people taking statins would reduce the number of heart attacks, particularly these first heart attacks. It's called primary pension. And the drugs are pretty cheap now. Most of them are generic. So this was all in favor of the guideline. Some critics, however, pointed out that many of the people who took the statins would never have had heart attacks in the first place. So they wouldn't really be getting the benefit. And there is a slight increase in risk for some things, most notably diabetes. And that's not a trivial thing. So people have to really weigh what are the benefits and risks from exposing many people to these drugs.

MARTIN: But it does seem that when it comes to these medical guidelines and the research they're based on, it all raises more questions than it answers.

HENSLEY: Absolutely right. And I think what's encouraging - to me, anyway - is that many of the guidelines are now recognizing the uncertainty. And they are explicitly saying that doctors and patients have to talk more about these trade-offs, these risks and benefits, and also, in a very explicit way, saying, figure out what matters to the patient. And so this is an invitation. Use this to your advantage to talk with your doctor and say, what are the risks and benefits from this? What could I get out of it? And by the way, here's what matters to me. The hardest part may be getting enough time in the exam room to actually have that kind of conversation. But it's worth trying.

MARTIN: Scott Hensley from NPR's Shots blog. Scott, thanks so much for explaining it to us.

HENSLEY: You're welcome.