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Rich, in terms of the question "how many people is it acceptable to harm to benefit one", How big is that number/ratio? 10-1? 100-1? 1000-1? 10,000-1?, an interesting deliberation may be gained from the legal literature in the context of capital punishment. Apparently, the attempt to quantify the ratio of false negatives (letting criminals go free) to false positives (accusing/executing people for the crime that they did not commit) dates back to 14th century when that ratio was 20:1 (it was considered that it is better that 20 guilty persons escape punishment than one innocent person suffers unnecessary). In 17th century, the ratio was as low as 5:1 , and apparently in modern America the ratio has increased to 1,000:1 (although in the countries that don't have the capital punishment the ratio approaches infinity!) ben From: Evidence based health (EBH) [mailto:[log in to unmask]] On Behalf Of Richard Saitz Sent: Sunday, November 27, 2011 10:02 PM To: [log in to unmask] Subject: Re: New breast cancer screening guidelines released Canada_underscoring the need for decision making based on evidence Colleagues, Some may be interested in the book: Welch G, Schwartz L, Woloshin S. Overdiagnosed: Making people sick in the pursuit of health. You might also be interested in the NY Times editorial by Welch G re breast and prostate cancer screening (these were issues addressed in various publicly unpopular ways within the past few years (prost CA revisiting this fall, breast CA screening a couple of years ago)(should come up on google). I think something that often gets mixed up in these debates (not by this group of course) is the distinction between screening asymptomatic populations, and diagnosis of people with symptoms or even screening people at high risk (a recommendation for screening asymptomatic people should not influence clinical practice with symptomatic patients-it might, but it shouldn't). Further, there is a distinction between screening tests that have at least some proven benefit (mammography), versus those that have insufficient evidence to know (likely breast self exam), versus those proven harmful (eg prostate cancer screening). At least for those with proven benefit one can examine what is known and then talk about the data... But I think Ben is right-it often comes down to how many people is it acceptable to harm to benefit one (especially when the benefits and harms accrue to different people. Surgeons, particularly before CT scans became routine for appendicitis, had to take out X normal appendices to make sure they weren't missing any cases. The general public was generally horrified to hear such a thing. How big is that number/ratio? 10-1? 100-1? 1000-1? 10,000-1? Of course the other issue is that one hears about people who have had cancers missed (the number one reason an internist is sued for malpractice). But one does not hear about individuals who were unnecessarily screened, even if they accrue tremendous harms (eg prostate ca screening leading to surgery and numerous complications...which was likely not necessary but will never be perceived that way by the patient). The numbers in the latter category may be large yet will never outweigh the one missed case, which is far likelier to influence public opinion and therefore policy. Best Rich ________________________________ From: Evidence based health (EBH) [mailto:[log in to unmask]] On Behalf Of Djulbegovic, Benjamin Sent: Sunday, November 27, 2011 4:07 PM To: [log in to unmask] Subject: Re: New breast cancer screening guidelines released Canada_underscoring the need for decision making based on evidence Rakesh, not belabor the value/risk attitude issue, it is instructive to read the actual Canadian Task Force recommendations: "This recommendation [weak recommendation, moderate quality evidence] places a relatively low value on a very small absolute decrease in breast cancer mortality and reflects concerns with unnecessary diagnostic testing and overdiagnosis (diagnosis of breast cancer that will not affect length or quality of life). Women who place a higher value on a small reduction in breast cancer mortality and are less concerned about the potential harms may choose screening." " To save one life from breast cancer over about 11 years in this age group (40-49), about 2100 women would need to be screened every 2 to 3 years; - 75 women would have an unnecessary breast biopsy; about 690 women will have a false positive mammogram leading to unnecessary anxiety and follow-up testing" And, inevitably we have to come to the most uncomfortable question of all: how much unnecessary procedures are worth saving one life? Best ben From: Rakesh Biswas [mailto:[log in to unmask]] Sent: Sunday, November 27, 2011 1:41 AM To: Djulbegovic, Benjamin Cc: [log in to unmask] Subject: Re: New breast cancer screening guidelines released Canada_underscoring the need for decision making based on evidence Thanks Ben, Amy, Kev, Ash, Adrian and Fiona for this very interesting discussion. "The guidance from the Canadian Task Force on Preventive Health Care, published in CMAJ, the journal of the Canadian Medical Association (doi:10.1503/cmaj.110334), says that women should not be urged to check their breasts for cancer on a regular basis or have their GP carry out an examination, because there was no evidence that doing so reduced mortality rates." Is it that a concept of 'evidence' which is currently completely dependent on 'mortality' and 'rates' is what makes a solution (ref-emails below) appear so difficult to attain? As Ben pointed out in an earlier post, one of the possible advantages of listening to or thematically analyzing 'patient and health professional perspectives' (through EMRs-a purported solution to the current problem) is the dissemination of 'familiarity.' The consequent learning generated from such solutions could perhaps make them a potential tool to tackle unmeasurable issues such as 'values' and 'suffering' without getting into a conflict between attitudes? regards, rakesh PS:-- COI: i am not keen about the label 'postmodernist' although i do find the concept of 'science' as socially sanctioned activity interesting (i wonder if it is 'soft clinical science' or 'hard basic science'). :-) On Sun, Nov 27, 2011 at 8:10 AM, Djulbegovic, Benjamin <[log in to unmask]<mailto:[log in to unmask]>> wrote: Kev, an interesting point-thanks. Indeed, if we agree that science is socially sanctioned activity (as postmodernists are never tired of pointing that out) that occur within the paradigmatic set of VALUES, it is possible that essentially the same evidence can be interpreted differently (NB evidence on screening mammography has not substantially changed during last decade or so, but recommendations have slowly began to change as new times have slowly but surely have started to embrace a new set of attitudes toward false positive vs. false negative recommendations, reflective of changing individual vs. societal values ). But, the question remains "whose values" should matter: the guidelines panels', or women who are the ones who have most to gain/loose. As Amy remind us, It is guidelines panels who allocate the risks and not the persons who suffer the risks. And that is the crux of controversy- with no easy solutions in sight. ben From: Evidence based health (EBH) [mailto:[log in to unmask]<mailto:[log in to unmask]>] On Behalf Of Dr. Amy Price Sent: Saturday, November 26, 2011 4:55 PM To: [log in to unmask]<mailto:[log in to unmask]> Subject: Re: New breast cancer screening guidelines released Canada_underscoring the need for decision making based on evidence Dr Kev, I agree, my daughter was caught in this because she was under 40 in the USA when screening was withdrawn. She was not at risk genetically as a great % of those who contracted BC are not according to what is 'known'; but she had a previous biopsy, this was not allowed as a consideration. Screening was refused by her insurance as was sonography. We paid, she was diagnosed with a phyloddes tumor and in the time it took to wrestle with the healthcare provider the tumour grew, so again she was charged and then told that the surgeon who stated categorically he was in the network ended up being out of network . This caused her to have to file bankruptcy when her previous credit score her whole life had been impeccable. Fortunately to date she has remained cancer free after surgery but I can't help but consider the toll this stress places on a compromised immune system and of the pain this thoughtless inhumane care caused. I have another 2 friends who because of this prevailing thought of cancer under forty not being probable had their cancers ignored, one woman's husband paid privately to have the lump excised and biopsied and was years later reimbursed whereas the other's cancer progressed to stage 3 in the time from finding a lump to biopsy to jumping the legal hoops and red tape. I feel that all aspects of the social environment need to be considered and that all evidence needs consideration inclusive of that that shows limited evidence for widespread genetic abnormalities . I understand that incidence may be rare for under 40s and that routine screenings may be a waste of healthcare dollars but at the same time there needs to be recourse and education so doctors and woman can make confident evidence based choices about their own care. I must admit I was chilled to the bone when I saw the comments about doing away with self exams as well as it is by this process that many of my contemporaries discovered the cancer in early stages and are alive today because of prompt effective intervention. I understand that a false positive is also distressing but surely nothing to compare with having to 'put your affairs in order' It would be illuminating to know the qualifications of those who are on these task forces, their COIs and their legal responsibility for the decisions they make which will ultimately impact lives. It would be good if those neglected could communicate with them directly and also those who are freed from being labelled no responders which of course ultimately could impact their future care as well. Best, Amy From: Evidence based health (EBH) [mailto:[log in to unmask]<mailto:[log in to unmask]>] On Behalf Of k.hopayian Sent: 26 November 2011 03:24 PM To: [log in to unmask]<mailto:[log in to unmask]> Subject: Re: New breast cancer screening guidelines released Canada_underscoring the need for decision making based on evidence Hi Ben, Not sure that I agree that this is just a question of attitudes to risk. While I accept that there is individual variation in attitudes to risk (meaning bad things) and risk (meaning the chances of those bad things happening), there is also a social dimension. That social dimension includes, amongst other things, the message broadcast by those perceived to be authorities, in this case, guideline developers and disseminators. And in many countries, guideline developers have recommended the provision of mammography screening based on their interpretation of the evidence as showing that screening reduces mortality. The disseminators have urged women to follow these guidelines. It is in this social environment that women must make decisions. Women who do not respond to invitations for screening will be seen as deviating from official policy and their peers who mostly do attend. Their computer record will flash up Non-Responder whenever they consult the general practitioner. Now if the guideline developers take the view that mammography is not effective in reducing mortality (which the Canadian Task Force appears to do) and go further and do not recommend it be provided (which the Task Force stopped short of doing), then the environment will be a very different one. Therefore, a further look at the evidence and further debate may well influence future recommendations. BTW, it is interesting to observe that the Can Task Force did not take that extra, terrifying step, of recommending that screening mammography be withdrawn. Social forces at work again?!? Dr Kev (Kevork) Hopayian, MD FRCGP General Practitioner, Leiston, Suffolk Hon Sen Lecturer, Norwich Medical School, University of East Anglia GP CPD Director, Suffolk [log in to unmask]<mailto:[log in to unmask]> http://www.angliangp.org.uk/ Making your practice evidence-based http://www.rcgp.org.uk/bookshop On 25 Nov 2011, at 19:20, Djulbegovic, Benjamin wrote: I think no further look at evidence will resolve the screening mammography question. This is a question of VALUES and how we weigh false positives (unnecessary biopsies, surgeries etc- regret of commission, of unnecessary) vs. false-negatives (missing cancer, delay in diagnosis, etc- regret of omission, of potentially failing to save lives). Because our risk attitudes inherently differ (there is no such a thing as "right" or "wrong" risk attitude), no guidelines panels can make recommendation for a woman facing decision whether to accept invitation to screening mammography. This is best summarized by Lesley Fallowfield in one of the papers to which Ash provided links provided below, and Fiona Godlee in her editorial when she says that she "speaks for many women when she admits that, despite her own detailed knowledge of the science, she is uncertain of the value of mammography screening. "I feel silly for attending screening, but scared not to do so." Ben Djulbegovic From: Evidence based health (EBH) [mailto:[log in to unmask]<mailto:[log in to unmask]>] On Behalf Of Ash Paul Sent: Friday, November 25, 2011 1:47 AM To: [log in to unmask]<mailto:[log in to unmask]> Subject: Re: New breast cancer screening guidelines released Canada_underscoring the need for decision making based on evidence Dear Paul, In this week's excellent issue of the BMJ, we have some very good articles on the subject of breast screening. Two of them are by members of this Group, Fiona Godlee and Klim McPherson: Mammography wars<http://bmj.com/lookup/doi/10.1136/bmj.d7623?etoc> Fiona Godlee Women in their 40s should not be screened for breast cancer, new Canadian guideline says<http://bmj.com/lookup/doi/10.1136/bmj.d7625?etoc> Adrian O'Dowd Breast cancer screening review: We need scientific consensus founded on all the evidence<http://bmj.com/lookup/doi/10.1136/bmj.d7529?etoc> Klim McPherson Breast cancer screening review: An appeal to Mike Richards<http://bmj.com/lookup/doi/10.1136/bmj.d7535?etoc> Michael Baum Breast cancer screening review: What should women do in the meantime?<http://bmj.com/lookup/doi/10.1136/bmj.d7544?etoc> Lesley J Fallowfield Regards, Ash From: Paul Elias <[log in to unmask]<mailto:[log in to unmask]>> To: [log in to unmask]<mailto:[log in to unmask]> Sent: Thursday, 24 November 2011, 17:14 Subject: New breast cancer screening guidelines released Canada_underscoring the need for decision making based on evidence http://www.eurekalert.org/pub_releases/2011-11/cmaj-nbc111611.php Best, Paul E. 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