Monthly Archives: June 2013

Minimizing Diagnostic Error: The Importance of Follow-up & Feedback

diagnosticindexI lost my composure recently after reading David Brooks column “Beyond the Brain” in the June 17, 2013, New York Times.  I tried to write a post in response to it, but it got too political and personal quick.  I decided that is not what I want to do here.  But this post is prompted by something personal.

In the spring of 2011, my then 57 year old sister went to her internal medicine doctor after experiencing a large amount of blood in her urine.  She was referred to a urologist who did several tests and scans and found no issues. In August 2012 after experiencing back and leg pain, she was diagnosed with bladder cancer of the renal pelvis-Stage IV.  She has been through chemotherapy, radiation, surgery, and now more chemotherapy.  She has not seen the same urologist or his group since the diagnosis.

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Bernanke and the Gist

NA-BW979_CAPITA_D_20130625180303Ben Bernanke, chairman of the Federal Reserve, gave a news conference last week.  Since then mortgage rates have jumped about half a percent along with 10 year treasury notes. The stock market is also down.  Interestingly, Bernanke appeared to be trying to calm things down and did his best to provide the detail that analysts, investors, and the press wanted without really changing anything that he had said before. My first reaction is that when the Fed is asked for more clarity, they are really being asked for a secret signal for when the rats should get off the ship. So Bernanke, like the public health officials trying to communicate about vaccines, is a risk communicator.

On June 26, 2013, David Wessel wrote his Wall Street Journal column “Capital” about Bernanke’s efforts, and provided some interesting comments.  Wessel indicated that maybe Bernanke did not “appreciate how hard it is to predict how markets will react to lengthy explanations.”  Or perhaps markets were just ready to change course and “Mr Bernanke provided the moment.”  Fuzzy trace theory seems to have a place here.  Over the last few years, Bernanke’s gist has been that the fed among all possible actors would do whatever it could to help the economy and reduce unemployment. His lengthy explanation last week indicated that he had been thinking a lot about being ready to change this.  Maybe that changed the gist from full speed ahead to easing off.  The slightly more complicated message changed the gist.

Goldman Sachs boss Lloyd Blankfein whose economists interpreted the news conference as “a hawkish surprise” was quoted by Wessel as saying before the news conference:  “Even if the Fed wants to change its rate slowly, at the first indication of change, the markets will change it quickly.  If you want to handle that in the best way, you create a little bit more uncertainty in the market in the less aggressive, less jarring way.”   We can hope that Bernanke is so confident about the economy that he thought that it was time to muddy up the gist and shake some of the “irrational exuberance” out of the markets. If the economy sputters, I hope that Bernanke can go back to a memorable positive gist to renew confidence about the Fed’s actions.

Blankfein makes an interesting point when he notes that at the first indication of change, the markets will change quickly.  This is almost like a phase change in physics where ice melts. You do not have to change the temperature much to have a completely different situation on your hands.  Public health vaccination communicators are concerned that this could happen with viral messages on the internet that undermine the advances made by vaccination programs.

Web 2.0 for Vaccination Decisions

vacindexThis post looks at a paper that was put together at a conference on risk perception and risk communication regarding vaccination decisions in the age of social media.  The paper: “Opportunities and challenges of Web 2.0 for vaccination decisions”, was published in the Journal Vaccine 30(2012)3727-3733.  Two of the authors are Cornelia Betsch and Valerie Reyna.  I think both of them are insightful.

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Fuzzy-Trace Theory- Experts and Future Direction


Experts are important in helping to make decisions about health and safety so their risk perception and decision processes are important to understand. Reyna gives as examples: the emergency room physician deciding about the risk of a patient for a heart attack, the meteorologist deciding about tornado risk, and a lawyer evaluating potential damage awards to decide to settle or go to trial.  Conventional wisdom is that experts apply precise analysis and numerical reasoning to achieve the best outcomes, while novices are more like to reason without analysis or numerical reasoning.

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Fuzzy Trace Theory- Risk Taking Framing Effects

negative framing_niallkennedyThis is the second part of my look at fuzzy trace theory. Reyna first compares the predictions of prospect theory to fuzzy trace theory with respect to framing effects in adults. Framing effects describe shifts in risk preferences from risk aversion when prospects are described in terms of gains to risk seeking when the same prospects are described in terms of losses.

Kahneman and Tversky cumulative prospect theory predicts risk seeking for gains with small probabilities and risk aversion for losses with small probabilities.  Reyna questions that numerical quantities or probabilities are necessary to observe framing effects.

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Fuzzy Trace Theory-Meaning, Memory, Development

gistimagesI discussed this theory briefly in the post Development Stages of Intuition and Analysis.  I am finally going to tackle it in a more detailed fashion. Valerie Reyna and her husband Charles Brainerd are the authors of fuzzy trace theory.  This theory is about twenty five years old, but has been ignored by the most renown psychologists so far as I can tell. The theory is supported by much empirical testing. Reyna and Brainerd moved together from the University of Arizona to Cornell and it seems that the theory has gained something of a foothold.  Reyna is a tireless researcher, speaker, and writer  and has also made something of a name for herself in the public press with false memory phenomena.  I find her ideas persuasive although not complete, and I find it frustrating that I have not found much discussion of her ideas among her colleagues. This is especially surprising since she was a student of Amos Tversky. Dan Kahneman has never mentioned it so far as I can tell.  If you know where to look, please let me know.  I am going to try to summarize the basic ideas in three separate posts based on her paper:  “A new intuitionism:  Meaning, memory, and development in Fuzzy Trace Theory” found in the May 2012 issue of Judgment and Decision Making.

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Everyone else is a hypocrite

hypocriteindexRobert Kurzban is an evolutionary psychologist and author of this book published in 2010.  If I were more organized, this book should have been discussed in the post Justifying our Decisions….  It includes another take on plausible deniability or that Larson Far Side where Larry unknowingly filled the Grand Canyon because the sign was posted in the other direction. Instead of Jonathan Haidt’s driver on an elephant, Kurzban suggests the press secretary as the model for the conscious modules of the brain.

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The Statistics of Health Decision Making-Therapy

stat2imagesGigerenzer says that we must teach risk literacy in medical school and statistical literacy to all in primary school. He and his colleagues go into considerable detail to say how this should be done. Teaching statistics early is not sufficient. It is also essential to represent probabilistic information in forms that the human mind can grasp. To this end, visual and hands-on material can enable a playful development of statistical thinking. For instance, tinker-cubes are lego-like units that first graders can use to represent simple events, to combine to represent joint events, and to count to determine conditional frequencies.

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The Statistics of Health Decision Making- Causes and Consequences of Illiteracy

statimagesGerd Gigerenzer has produced much work that is relevant and easy to understand for the laymen.  Gigerenzer has defended the effectiveness and our abilities to use heuristics.  He has also tirelessly promoted statistics education and transparent presentation of statistical information.  This post tries to summarize some unique and interesting material with respect to the causes and consequences of our statistical illiteracy.

Gerd Gigerenzer along with Wolfgang Gaissmaier, Elke Kurz-Milcke, Lisa M. Schwartz, and Steven Woloshin suggest that the long opposition to health statistics can be traced back to the struggle between three 19th-century visions of the physician: artist, determinist, or statistician.  They argue that these professional ideals go hand in hand with patients’ corresponding ideals, which even today determine the mixture of feelings about health statistics: The artist embodies paternalism and requests blind trust from the patient, the determinist strives for perfect knowledge of causes and invites the illusion of certainty in patients, and the statistician relies on facts rather than medical charisma, paving the way for shared decision making. The first two ideals effectively deter interest in health statistics.

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The Statistics of Health Decision Making-Statistical Illiteracy

statanalysis_03This will be the first post of a three-part series. They will all be based on a 2008 monograph that appeared in Psychological Science in the Public Interest, entitled:  “Helping Doctors and Patients Make Sense of Health Statistics.” Gerd Gigerenzer was the primary author.  I have started posts on numeracy, especially health numeracy, based on journal articles, but they tended to be focused on the public’s generally poor numeracy skills.  This always stopped me in my tracks, because it left out the doctors who have skills much like the public, and it left out the researchers, screening test providers, drug makers, and device makers who tend to have excellent skills.  They sometimes use those skills to take advantage of the doctors, patients, and the public(for my purposes journalists are just part of the public).  This monograph puts  the pieces together.

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