A few weeks ago, I presented Family Medicine Grand Rounds at Georgetown University School of Medicine on resolving conflicts between screening guidelines. During the question and answer session, Department Chair James Welsh, MD asked how evidence from carefully conducted clinical trials can possibly overcome powerful emotional stories of “saved lives.” I answered that evidence-based medicine’s supporters must fight anecdotes with anecdotes. For every person who believes his or her life was extended by a PSA test or a mammogram, statistics show that many more are temporarily or permanently injured as a result – and their stories matter too. As blogger Kevin Pho, MD wrote about the USPSTF’s recent prostate cancer guideline, “Task Force advocates will need to put a human face on the complications stemming from prostate cancer screening” in order to convince physicians and patients that it’s okay to stop. Indeed, news stories about PSA test-related complications such as this one by Associated Press writer Marilynn Marchione will go a long way in balancing the scales.
An insightful commentary published in JAMA last month took this point one step further by asserting that narratives deployed to support evidence-based guidelines should include not only patients’ stories, but the story of the guideline developers themselves:
“Typically, experts present a “clean” version of their findings without any narrative about how they made sense of the data. This fulfills the scientific virtues of objectivity, coherence, and synthesis. When the USPSTF released its report on screening mammography to much controversy, it included no narrative about the process. Only later was the story of the task force deliberations revealed. This narrative, with multiple characters operating within the context of historical precedents, timing mandates, and a messy political milieu, created a substantially more compelling perspective. But the account came too late to engage a confused and angry public with the task force’s conclusions.”
To the two certainties of life, death and taxes, add another two: mammograms and controversy surrounding mammograms.
The Canadian National Breast Screening Study (CNBSS) has reported results of its long term follow-up in the BMJ: no survival benefit of screening mammograms.
To paraphrase Yogi Berra “it’s mammography all over again.”
Is the science settled then?
Before I wade further it’s important to understand what is implied by “settling the science.”
Einstein said “no amount of experimentation can prove me right; a single experiment can prove me wrong.”In physical sciences a theory need only be disproven once for it to be cast aside. Heliocentricity cannot coexist with Ptolemy’s universe. The statement “all swans are white” is disproven by a single black swan.
What do we do with the studies that showed survival benefit of screening mammograms? Why does the CNBSS not close the debate over mammograms, like Galileo did with celestial egocentricity?
The simple and simplistic answer is because there are powerful advocacy groups, special interests; the pink-industrial complex who have a vested interest in undermining the science.
But that lends to conspiratorial thinking. Special interests cannot undermine Maxwell’s equations or Faraday’s laws just because they do not like them.
The testability of Maxwell’s equations is inherently different from verifying that screening mammograms increase life expectancy. We must acknowledge two types of science; the former, physical science, a hard science; the latter, a hybrid of biology and epidemiology, soft science.
Soft science is a misnomer. There is nothing soft about performing a randomized controlled trial (RCT), the methodological gold standard; in ensuring factors that falsely augment or attenuate impact of screening mammograms are evenly distributed, data reliably collected, cause of death accurately recorded and correctly inferred. But the human factor and all its inevitable foibles are unavoidable in soft sciences.
It’s fitting that this year’s ACOG meeting was held in New Orleans, because navigating the 2013 ASCCP Pap Smear Management Guidelines presented there feels like trying to make my way through the Mississippi bayou. The guidelines include 18 different algorithms encompassing almost any combination of pap and HPV abnormality we docs are likely to encounter among our patients. But all tributaries lead to the same place, where we achieve optimal reduction in cervical cancer with minimal harm.
Cervical cancer prevention is a process with benefits and harms. Risk cannot be reduced to zero with currently available strategies, and attempts to achieve zero risk may result in unbalanced harms, including over treatment. …optimal prevention strategies should identify those HPV-related abnormalities likely to progress to invasive cancers while avoiding destructive treatment of abnormalities not destined to become cancerous. Adopted management strategies provide what participants considered an acceptable level of risk of failing to detect high-grade neoplasia or cancer in a given clinical situation.
I’m not even going to try to spell out everything in the guidelines, which come from the American Society of Colposcopy and Cervical Pathology (ASCCP), except to say that they represent further movement away from aggressive screening and treatment of pap smear abnormalities, especially in younger women, in whom treatment carries small but real childbearing risks. The guidelines are increasingly reliant upon HPV testing to determine who and how often to screen, and when to treat. They also acknowledge the role of testing for HPV 16 and 18 as a way to be sure that those women with adenocarcinoma of the cervix (which is less likely to show up as cancer on a pap smear) are identified and treated.
From the guidelines-
The U.S. Preventive Services Task Force formally published its recommendation for routine HIV testing for all individuals age 15 to 65 in the Annals of Internal Medicine this week. An editorial and patient materials are all available free to anyone with an Internet connection. Many people who work in HIV hoped that this would finally move HIV into mainstream medicine.
With a U.S. Preventive Services Task Force Recommendation, patients don’t need to ask for the test, it would become a routine blood test like many others, stigma would be reduced, and insurance would likely cover it. The evidence backs it. However, within 24 hours of the Task Force Recommendation going up online, the American Academy of Family Physicians questioned age 15 as the logical starting point, instead urging that testing begin at age 18. This is just some of the resistance that the medical community is putting forward now.
Several months ago, I spoke with Roger Chou, MD, MPH, associate professor of internal medicine at Oregon Health and Science University, Portland, Oregon, who headed the evidence review for the U.S. Preventive Services Task Force. “About 25% of people who have HIV and are not aware of it,” Chou said. “They have no identifiable risk factors.”
Other reasons why data to back routine HIV testing are in, include that “the screening test is highly accurate, we have direct evidence from randomized controlled trials that we can reduce the risk of transmission by 90%, and that you can’t trust what your patient says, , or that patients don’t always think that they are at risk,” said Chou.
Recently, the US Preventative Services Task Force reiterated its recommendation that women not undergo routine screening for ovarian cancer. This was remarkable, not simply because it was a recommendation against screening, but because the task force was making the recommendation again, and this time even stronger.
The motivation for the recommendation was simple: a review of years’ worth of data indicates that most women are more likely to suffer harm because of false alarms than they are to benefit from early detection. These screenings are a hallmark of population medicine—an archetypal form of medicine that does not attempt to distinguish one individual from another. Moving beyond the ritualistic screening procedures could help reduce the toll of at least $765 billion of wasted health care costs per year.
We already know the common changes in the DNA sequence that identify people who have higher risk of developing ovarian, breast or prostate cancer and most other types of cancer. Consumers can now readily obtain this information via personal genomic companies like 23andMe or Pathway Genomics. But we need to do much more DNA sequencing to find the less common yet even more important variations—those which carry the highest risk of a particular cancer. Such research would be easy to accomplish if it were given top priority and it would likely lead to precision screening. Only a small fraction of individuals would need to have any medical screening. What’s more, it will protect hundreds of thousands of Americans from being unnecessarily harmed each year.
The U.S. Preventive Services Task Force is at it again. This time, the government-appointed panel is on fat patrol. Its review of the medical literature found that diet and exercise combined with group counseling beat popping a pill when it comes to controlling weight.
For those with short memories, USPSTF is the government panel that in the midst of the health care reform debate had the temerity to suggest the evidence was iffy on the wisdom of mammography for women under 50. Check with your doctor before deciding if an early start to routine breast cancer screening was right for you, they said.
Conservatives had a field day. “We don’t know how far government will go in this bureaucracy,” cried Rep. Michele Bachmann, R-Minn., who a few months later launched her presidential campaign. “This is how rationing begins,” intoned Rep. Marsha Blackburn, R-Tenn.
When it comes to obesity, though, a little food rationing is just what the doctor ordered, according to the latest from the USPSTF. How one rations matters, however.
“With drugs, when people stop, they gain the weight back,” said David Grossman, a senior investigator at Group Health Research Institute in Seattle and chairman of the 16-member panel that issued the updated guidelines on obesity prevention on Tuesday. “This is a lifestyle problem. If you don’t change your lifestyle, drugs are not likely to provide a long-term solution.”
Michelle Obama wasn’t taking the easy path when she chose the obesity epidemic and childhood obesity in particular as her main cause. Since the late 1970s, the number of people considered obese grew by half and now totals 32 percent of men and 36 percent of women. One in 20 Americans are now considered morbidly obese. By 2030, if nothing is done, those numbers are expected to grow to over 40 percent obese with over 10 percent morbidly so.
Dr. Timothy Wilt, a member of the United States Preventive Services Task Force, stood in front of the American Urological Association audience and explained why the task force could not recommend that men undergo routine PSA screening. At most, he explained, the test had been shown to benefit one out of 1000 men. Meanwhile, the test would cause hundreds of men to experience anxiety, and scores of them to experience impotence and incontinence from unnecessary treatments.
Twenty minutes later, I stood behind the same podium and asked the audience members to raise their hands if they disagreed with the task force’s conclusion. Ninety percent expressed their skepticism. What happened in the time between Wilt’s presentation and mine reveals a great deal about why experts cannot agree whether screening tests, like the PSA in middle-age men or mammograms in 40-year-old women, bring more benefit than harm, and about what psychological forces impede our ability, as a society, to figure out what basic bundle of healthcare services all insurance companies ought to pay for.
Wilt’s presentation was a model of scientific clarity. He explained that only two randomized clinical trials were conducted with enough scientific rigor to provide useful estimates of whether the PSA test saves lives. One trial showed no benefit and the other revealed the one in 1000 number which the task force took as the best case scenario. Wilt was followed on stage by Ruth Etzioni, a biostatistician at the Fred Hutchinson Cancer Research Center in Seattle. Etzioni presented a statistical model suggesting that the PSA test benefited many more than one in 1000 men.
There’s something compelling about the personal narrative that vast mountains of quantitative data cannot rival. Anecdotes are, quite simply, powerful. They tap into our shared humanity, making something seem somehow more real by putting a face on it. This is why, if you follow politics for very long, you will find numerous cases of policymakers championing issues that have touched their own lives in some way. For example, Senator X doesn’t care about issue Y, until they discover that their son or daughter is affected by it. Then, almost overnight, they seem to care more about issue Y than almost anything else. Such a shift is completely understandable, but often out of proportion to the true scale of the issue in society.
In health policy, the personal narrative can also be very powerful. In fact, the journal Health Affairs routinely runs a “Narrative Matters” section that puts a face on the health care issues of the day. It is absolutely critical that health policymakers, health services researchers, and others, not lose sight of the fact that their work and the subsequent decisions it informs, are based on real people. However, it is equally critical for objectivity to be maintained, and narrative can threaten our work in this regard.
The numbers are stark. According to the United States Preventive Services Task Force, for every man whose death from prostate cancer is prevented through PSA screening, 40 become impotent or suffer incontinence problems, two have heart attacks and one a blood clot. Then there’s the psychological harm of a “false positive” test result, which is 80 percent of all “positive” tests. They lead to unnecessary worry, follow-up biopsies, physical discomfort and even harm. Final grade: D.
Three men close to me have been diagnosed with prostate cancer late in life. Each was around 70. My dad, already in throes of advancing Alzheimer’s disease, did what the doctor ordered (actually, I suspect my mom told my dad to do what the doctor ordered). He had surgery. And for the last six years of his life, which until his final three months was at home, she cleaned up after him because of his incontinence. My neighbor made the same choice. He quietly admitted to me one day that he suffers from similar symptoms, but he is grateful because he believes his life was saved by the operation. And my friend Arnie? I’ve written about him in this space before. He was diagnosed at 70, and being a psychiatrist with a strong sense of his own sexual being, understood the potential tradeoffs. He decided to forgo treatment. He died a few years ago at 90. I never learned the cause.
So what does it mean that PSA testing gets a D rating?