Posted by Gary Schwitzer in Screening
Don’t miss Gil Welch’s editorial in the New York Times, “If You Feel O.K., Maybe You Are O.K.” Excerpt:
Screening the apparently healthy potentially saves a few lives (although the National Cancer Institute couldn’t find any evidence for this in its recent large studies of prostate and ovarian cancer screening). But it definitely drags many others into the system needlessly — into needless appointments, needless tests, needless drugs and needless operations (not to mention all the accompanying needless insurance forms).
This process doesn’t promote health; it promotes disease. People suffer from more anxiety about their health, from drug side effects, from complications of surgery. A few die. And remember: these people felt fine when they entered the health care system.
Another noteworthy piece today is the blog post by Dr. Kenny Lin, “Rethinking shared decisions in prostate cancer screening.” It’s a provocative piece but Lin’s track record – as board-certified Family Physician, Associate Deputy Editor of the journal American Family Physician, instructor of family and preventive medicine at the Georgetown University School of Medicine, Uniformed Services University of the Health Sciences, and the Johns Hopkins University Bloomberg School of Public Health, and former staffer at the US Preventive Services Task Force – is all the calling card he needs.
Addendum on March 5:
On The Incidental Economist site where Lin’s post was being discussed, Shannon Brownlee left this comment:
I disagree with him on this one, despite having written an article in the NYTimes Magazine that strongly supported Kenny’s work at the US Preventive Services Task Force, which found that PSA testing does not offer a mortality benefit. Here’s the link for those who are interested:
Shared decision making is not about getting the patient to do what the doctor wants him to do, which judging from Kenny’s blog he thinks it is (and his opinion about the PSA test is, understandably, “Just don’t do it!” ).
Telling patients what to do is not the point of shared decision making, and frankly as a patient, I find myself bristling when doctors, even those who are caring and well-informed, insist that they know best about what I want to do with my body. The point of shared decision making is to help patients: a) understand that ELECTIVE decisions mean the patient has a choice; b) understand the tradeoffs involved in each of the choices; and c) come to a decision that is in keeping with their values and preferences.
What I think Kenny is saying (sorry to put words in his mouth!) is that PSA testing should not be considered an elective test. I don’t know what the right answer is there, but there is a reasonable case to be made that some men might want it, even after understanding as much as Kenny does about how lousy the test is. And it is a lousy test — as one researcher puts it, PSA is about as good at predicting your chances of having prostate cancer as the color of your eyes. And yes, the randomized controlled trials did not find an all-cause mortality benefit from PSA testing. But there’s evidence to suggest that it might possibly reduce your chances of dying from prostate cancer, though not by much. So for a man who would rather die of ANYTHING but prostate cancer, even the treatment for it, then maybe he wants the test. He values avoiding a prostate cancer death, and while early diagnosis is no guarantee that he will, he might.
So while I think getting a PSA test is a really bad idea, and I don’t think I would get one myself if I were a man, and I’m glad my husband decided to forgo the test after viewing a patient decision aid, maybe it should still be considered an elective decision.
What do the data say about shared decision making and its effect on patient decisions? A Cochrane Collaboration systematic review of more than 80 prospective RCTs comparing patients who had access to a patient decision aid (for lots of different elective decisions) and those who got usual care (the doctor tells them about their choices) found that patients who have access to an aid are better informed about the risks and benefits involved in their choices; are more realistic about those tradeoffs; and are on average 20% less likely to choose more invasive options. (That last finding is why policy makers get all excited about shared decision making.)
When you look specifically at studies of shared decision making for PSA testing, it’s not so clear that men are less likely to choose the test. There are a couple of possible reasons. I can’t pretend to have looked at all of the studies, but from a few that I’ve seen, it’s not surprising that men opt for the test because the so-called patient decision aid that was used urged them to get tested. The other reason I think its hard to dissuade men from getting tested is we have been beating the screening drum in the US for a long time. It is an article of faith that catching cancer early is universally good. It is going to take a long time to unlearn that myth.
Conclusion: discarding all of shared decision making on the basis of PSA testing is a bad idea.