Ask Dr. Hallberg: New studies cast confusion on conventional wisdom

Dr. Jon Hallberg
Dr. Jon Hallberg is assistant professor in family medicine at the University of Minnesota, and medical director at Mill City Clinic. He is a regular medical analyst on MPR's All Things Considered.
Photo courtesy of Dr. Jon Hallberg

Flu shots aren't as effective as we used to think and neither is the PSA screening for prostate cancer. Lately, it seems every week new data contradicts conventional wisdom in the medical field.

MPR medical analyst Dr. Jon Hallberg spoke with MPR's Tom Crann this week about the studies and what they mean for patient care. Hallberg is a physician in family medicine at the University of Minnesota and director of the Mill City Clinic.

Tom Crann: We hear all of this data, whether it's about flu shots or PSA tests — two big recent ones. What do patients really need to know when they come into the clinic?

Dr. Jon Hallberg: I think they need to know, first of all: How good are these studies? In these two cases, these are very good studies. This is the kind of thing that we do need to sit up and pay attention to.

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Crann: And how do we know what is a good study?

Hallberg: If you're just listening to the headlines or you're just glancing at the paper, it's hard to know because there's not often a clue as to whether they're good studies or not, but in both of these cases, the flu shot study that was in Lancet and the new PSA recommendations, they looked at lots and lots of well-crafted studies over time and then came to these conclusions.

Crann: So it's time and also numbers, here? The numbers don't lie?

Hallberg: That's kind of the harsh reality with this, and I think that's one of the things I've been really thinking a lot about lately is that these numbers, I mean that's why we do this because it's unemotional, and it tells us what we need to know, and it makes us change behavior. And sometimes we're doing things because we think it's the right thing to do, but when these well-done studies tell us otherwise, we really have to rethink our priorities and how we're doing things.

Crann: So, some things, though, that we've taken for granted over the years are being challenged. There's some confusion about it. Is there a positive upside here, as you see it?

Hallberg: Oh, there's no question. I mean I think that in the case of the PSA testing, that blood test was never designed to be a great screening test for prostate cancer. And I think all my urology colleagues will acknowledge that as well. We need a better test that can tell us: Is this a benign form of prostate cancer or is it an aggressive form of prostate cancer that we do need to do something about? In the case of flu shots, that study didn't say that they're not effective. They're just not as effective as we would like. So in both of these cases, we need better tests, and these kinds of findings are going to push researchers and push policy makers in the direction of getting better tests available to us.

Crann: These contradictory tests can often drive medical progress?

Hallberg: I think that's exactly what they do, and especially when they're well done like these, people really do sit up and take notice.

Crann: So things are shifting. There are shifting standards, especially from a patient perspective. How do you deal with that in the clinic?

Hallberg: First of all, we look at the quality of the studies. We field the questions as they come in. These studies are very impersonal, and my job as a family physician is to make them personal, and I think that that's kind of where we're going with this, too. We really have to bring this stuff down to the ground level, and in some cases, it will make no difference, depending on family history, preference, anxiety, you name it. There are so many different variables at play that determine how we extract this data and make it practical and bring it into the clinic.

Crann: And that's been a relatively noticeable shift or change for you?

Hallberg: Well, I would have to say in the last couple weeks, it's like virtually every visit that we have that's a physical exam or a preventive visit of some kind, there are some questions coming up about the findings of these studies?

Crann: And how do you counsel patients who seem just confused by it all or even skeptical that, 'Well, that's this week. Next week they'll be something else.'

Hallberg: I think I honestly start by telling them I'm a little confused myself sometimes, and that this stuff, it's not the kind of thing where overnight we're going to shift the way we do things. It's sort of a subtle drift, subtle, small changes one thing at a time. And it really does come down to the patient and what are their concerns and how does this information fit into their particular case.

(Interview edited and transcribed by MPR reporter Madeleine Baran)