Monday, 19 February 2018

What are the objectives of cancer prevention programs?








Vinay Prasad and Adam Cifu in "Ending Medical Reversal, Improving outcomes, Saving lives" affirmed that in order to interpret the meaning of secondary cancer prevention programs, three objectives must be kept in mind: 1) cancer ought to be discovered ahead of time, 2) specific mortality ought to be reduced and 3) overall mortality should be decreased.

The authors say that what really matters is objective number 3, given that the first two are purely instrumental. After all, if a healthy person accepts a screening, this is supposed to be because he or she wants to live longer. Unfortunately, the data shows that preventive programs (cancer of the colon, prostate, breast, cervix and lung) obtain the following results (with small nuances among them): a) objective 1: achieved, b) objective 2: weak, and c) objective 3: not reached.

The book contains an evaluation of a colorectal cancer prevention program (30 years of follow-up) that registered a specific mortality (objective 2) of 1.28%, while in the control group the figure was 1.92% (a significant difference), but when the general mortality was analyzed (objective 3), the comparison was between 71.11% and 71.09% (not significant). The survival of people is influenced by many factors, most of them not related to the healhtcare, but if we stick to our environment, it could happen that an intensive policy in the detection and early treatment of cancers achieved respectable successes in goal 2, but that, on the other hand, would lead to shortening life as a consequence of the aggressiveness of the therapies used.

If we focus on objective 1, the authors illustrate that things, on the theoretical level, should go as follows:

At the commencement of the preventive program, many more cancers should appear in the initial stage (subclinical) and some more in advanced stages (the hidden ones). If the program achieves its first objective, after a certain time, it should be seen how the increase in incipient cancers would decrease the number of advanced cases, which would be a prelude to the fact that it’s on the way to achieving goal 2.

With this graph in mind, I read an evaluation of the Dutch breast cancer prevention program "Effectiveness of and over diagnosis from Mammography screening in the Netherlands: population based study" (all women aged 50 to 75 years with a mammogram every two years for a period of 24 years, from 1989 to 2012), which shows the graph on the right. As observed, the detection of women with stage 1 cancers has increased significantly and, to a lesser extent, carcinomas in situ, but there is no significant fall in the incidence of stage 2-4 cancers, which indicate that objective 1 is having problems, as the following conclusions of the work show:

a) The Dutch breast cancer prevention program is having a very small (not significant) impact on reducing the number of breast cancers in advanced stages.

b) The induced over diagnosis reaches between one third and one half of the cancers detected, which means that a considerable number of women receive disproportionate treatment of tumours that would not have reached more advanced stages.

c) Specific mortality has had a significant decrease since 1995, despite the fact that researchers have only managed to attribute to the prevention program between 0% and 5% of said fall (according to the adjustment scenario) and up to 28% to improvements in treatments.

d) There is no reference to improvements in objective 3, the true purpose of preventive programs.

If you are tempted to undergo a secondary cancer prevention program (or influence someone to do so), don’t forget to ask about the three objectives, but especially insist on the third.

Cristina Roure has published a post about Prasad and Cifu’s book by: "I do therefore I am or the bias of intervention in medicine"


Jordi Varela
Editor

Monday, 12 February 2018

Medical schools: reductionism versus empiricism








The current competitive drive has reached the medical schools to the extent that it now delivers batches of new doctors with higher scientific preparedness whose priorities are influenced by their impact, competitiveness for research funds and, to a lesser extent, clinical practice. Young doctors know that in order to fight for the most coveted positions they will have to show a curriculum full of publications, while the clinical skills, although present, will not be the element that differentiates them. What is apparent is that educational reforms are part of the mechanism which is focused on academic success.

Monday, 5 February 2018

Are we all mentally ill? On the subject of Allen Frances








Allen Frances, psychiatrist professor emeritus of Duke University (USA) led the working group that developed the DSM-4 (Diagnostic and Statistical Manual of Mental Disorders). I follow the activity of the author, always critical and always documented on Twitter (@AllenFrancesMD) and, unfamiliar with the framework of psychiatry, a question began to run through my mind. How could it be that someone who had led the fourth edition of the DSM, was now the most lucid voice against the excesses of modern psychiatry? If I wanted to know the answer, I had no choice but to read his latest book "Saving Normal. An insider's revolt against out-of-control psychiatric diagnosis, DSM-5, big pharma and the medicalization of ordinary life"

Monday, 29 January 2018

The old is not an enemy of the new: quality standards for health institutions

Mª Luisa de la Puente




This provocative title intends to join the debate that appeared in JAMA this year on what are the quality results that an institution should establish and publish. Common objectives among institutions, from one or different countries for certain diseases selected by international agencies? Or specific objectives of each institution established according to their priorities and the preferences of their professionals?

Professionals from Kaiser Permanente (KP) and from the Department of Veterans Affairs Center (VA) and the Joint Commission Accreditation Agency (JC) disagree. The authors of KP/VA recognize that the measurement and publication of the results of certain prioritized diseases have undoubtedly contributed to the improvement of quality, but they believe that, while continuing to focus on the performance of accounts, it’s necessary to establish innovative formulas for measuring results.

Monday, 22 January 2018

The paternalism of presenting the glass half full or half empty

Pedro Rey



In previous entries, both Cristina Roure and Jordi Varela have talked about how cognitive biases and, in particular, our difficulty in understanding what probabilistic calculations really mean, can affect important decisions about our health. Today I want to show you an example, originally due to psychologists Daniel Kahneman and Amos Tversky, about the importance of the way in which health information is presented in cases in which it is necessary to make a clinical decision, given that there is uncertainty and thus, there exist different possible options which may not offer certain results. In order to better understand the example here presented, I suggest that after reading the following paragraph, you stop for a second to think and decide, before moving on to read the paragraph that follows.

“Imagine that you are a health manager who must decide between two possible measures in the face of the outbreak of an epidemic that is expected to kill 600 people. The information you have about the consequences of the two measures you should choose is as follows: if you decide to take measure A, you know with certainty that 200 people will be saved. If you decide to take measure B there is a 1/3 chance that the 600 people will be saved (and therefore, a 2/3 chance that no one will be saved). Which of the two measures would you choose?”  Please take a moment to think about it and write it on a piece of paper before continuing reading.

Imagine now that, faced with the same epidemic, you must choose between these two other measures. If you choose measure C, 400 people will die. If you choose measure D, there is a 1/3 chance that no one will die (and a 2/3 chance that 600 people will die). Which of the two measures would you decide now?

Having read the two paragraphs, you have probably already realized that there exists contradiction: measures A and C are identical in their expected consequences, as are measures B and D. However, it’s likely that you, like 72% of the subjects of multiple experiments who are asked to decide between A and B, may have chosen A, while, like 78% of the subjects who are asked to choose between C and D, you may have chosen D in the second question. How can this inversion of preferences occur?

Kahneman and Tversky, based in evidence from simple experiments like the one I have shown you, are responsible for the so-called "prospective theory", which offers an explanation. Summarizing it briefly, the theory says that human beings suffer more from negative events than what they enjoy from positive events, which leads us to behave as risk-averse when dealing with positive outcomes, and instead behaving like risk-lovers when faced with events which may have negative consequences. When we must choose between A and B many of us value more the certainty of saving 200 lives with measure A than taking the risk inherent to measure B, which with a low probability will save even more people. However, when it comes to assuming deaths, i.e., when choosing between C and D, we feel better when taking measure D (equivalent to B), which with low probability can achieve not deaths, than when taking measure C (equivalent to A) which assures us that we’ll have to take responsibility for the death of 200 people.

The problem presented by this example is not so much that it demonstrates that human beings are contradictory, which barely surprises us anymore, but that it opens the door for us to be manipulated when making decisions, merely by how the data is presented to us. This manipulation capacity is of particular importance in clinical practice where, for example, in an environment in which an attempt is made to promote shared decision making between doctor and patient about which treatment to follow, the doctor can continue to exercise full control over the patient through presenting the information of the healing possibilities or possible side effects in a positive or negative way. Therefore, it’s important to recognize that, if you really want to favor freedom of choice in situations that by definition involve risks, and thus probabilities, it’s necessary either to move towards greater education of those who receive the information so that they are able to interpret it correctly being aware of their own cognitive biases, or to do an enormous exercise of honesty and exposing this type of mind tricks, dedicating enough time to helping others  understand in an objective way, and not biased by our own self-interest, the expected consequences of their decisions, in some cases literally of life or death;  Give me freedom of choice or paternalism based on the specialists’ expertise but don’t disguise one as the other.

Monday, 15 January 2018

The orientation to the patient: a health service as a "service"

Sophia Schlette




One year ago, while I was still working for Kaiser Permanente, I was invited to give a talk on primary care concepts in an adult education academy in the vicinity of Berlin. I thought I would present a theoretical framework of evaluation, based on evidence, consisting of ten dimensions, similar, but not identical, to the ten building blocks of Bodenheimer already presented in this blog. I arrived on the previous afternoon and saw the participants with a certain air of frustration in being saturated with so much theory. The models and concepts of the talk had little to do with the experience in the German medical practice or with the doctor-patient relationship in real life. In Germany, if you go to the doctor, you have to take half a day off. Wait up to 40 minutes, despite having an appointment just to have 5 precious minutes with the doctor. Typically, neither the doctor nor his employees will give any explanation, nor apologize for the delay. There is no electronic medical record everywhere and where there is, the doctor begins to read it only when the patient is present: “Here’s the recipe. Have a good day. Goodbye” This is the German system, as we know it since childhood.

Monday, 8 January 2018

“The patient will see you now” on the subject of Eric Topol








Eric Topol, Director of Scripps Translational Science Institute, published in 2012 "The Creative Destruction of Medicine" and in 2015 "The patient will see you now. The future of medicine is in your hands." For a long time I had this last book on the waiting list and finally I could read it taking advantage of the holidays. It’s an important work, which talks about technology based on in-depth knowledge of clinical practice. It’s a literary piece, for my taste, a bit too overloaded, to the extent that, in some chapters, it’s difficult to follow the thread of the main thesis, but despite this, I have to admit that the contributions of the professor of genomics (and cardiologist) are relevant and I think they deserve to be discussed.