“Perhaps the main obstacle to changing the current system is that it isn't in most doctors' interest to try to change it.”
There are in fact two things, science and opinion; the former begets knowledge, the latter ignorance.
HippocratesLaw (c. 375 BC)
When Lewis Thomas famously dubbed medicine “the youngest science,” he meant not to suggest its immaturity, but rather to celebrate the contributions of fields like biochemistry and molecular genetics to human health. Obviously, advances in the life sciences have produced important innovations in diagnostics, drugs, and medical devices. Ironically enough, however, when it comes to applying the scientific method to determining which treatments and procedures provide the most (and least) benefits, medicine remains in the dark ages. Indeed, according to David Eddy, a cardiac surgeon turned mathematician who coined the term “evidence-based medicine” (EBM), less than 20 percent of what doctors do is supported by hard evidence.
Evidence-based medicine—and its cousin, “comparative effectiveness”—would seem, at first glance, to be common sense. After all, who wants medicine based on mere opinion? If outcomes data confirm a treatment’s benefits, doctors should use it; if it’s harmful, they shouldn’t. And if the data are inconclusive, the effects of the treatment unclear, doctors should be conservative, especially when considering therapies that are expensive or risky. But if we take Eddy’s 20 percent figure seriously, EBM, if it were mandated tomorrow, would exclude most of standard medical practice.
Since the early 1980s, John Wennberg and his colleagues at Dartmouth University have published a stream of research that highlights startling regional variations in American medical practices. Huge deviations occur from state to state and even from one county to another. Geography, in a word, trumps science. Depending on where she lives in Vermont, a woman could face an eight-fold difference in her chances of undergoing a “routine” hysterectomy. As for the chronically ill, Wennberg observes, “the frequency of physician visits, diagnostic testing, and hospitalization and the chances of being admitted to an intensive care unit depend largely on where patients live and the healthcare system they routinely use, independent of the illness they have or its severity.”
Patients blithely assume that their doctors’ judgments are grounded in science. But Wennberg’s colleague, Elliott Fisher, has demonstrated that people with chronic diseases living in high-cost areas, especially people who get most of their healthcare from top-flight academic medical centers, do not enjoy better outcomes than patients living in low-cost regions. This means that the way physicians manage chronic illness in low-cost regions does not involve withholding valuable care, Fisher concluded, but instead that high-cost systems are inefficient, wasting resources. More healthcare, and higher-priced medicine, does not translate into better health.
Of course, nobody intends to be wasteful and inefficient, or to endanger patients. What limits doctors’ ability to choose the best approach to care, David Eddy told BusinessWeek, “is the human mind.” Many patients suffer ripple effects from multiple disorders. Someone who’s obese and diabetic is also likely to suffer from hypertension, sleep apnea, and depression. Treating any one condition affects the others. Meanwhile, science and technology have exponentially increased what is known and what can be done for each condition. “The practice of medicine, the biology of disease and human variation, are way too complicated for the human mind,” Eddy concluded, “even the mind of a medical expert. And when we try and do it in our heads alone, we make mistakes.”
Without comprehending all of the outcomes data for different treatments, and adjusting for individual patients’ co-morbidities, physicians rely on personal judgment, what their peers do, along with rules and traditions received from their training. Simple habit and tradition explain, for instance, why so many doctors continue to order annual screening chest X-rays long after epidemiological studies have proved them worthless.
Ideally, EBM would deal with the many problems of collecting, interpreting, and disseminating data, serving as a kind of GPS for clinicians as they navigate the complexities of patient care. But in early 2008, physicians and the medical technology industry remain skeptical. While in principle they agree that the applications of treatments, procedures, and products should be based on evidence, they diverge on what this would mean in practice. Thanks to the Internet, scores of new clinical studies appear daily. How are these to be sorted, evaluated, correlated, and analyzed for quality and applicability? Which studies are valid? What constitutes sufficient evidence to dictate practice guidelines? What is one to do when competing medical interests introduce plausible evidence for conflicting claims? How can evidence from population-based studies be applied to individual patients? And, perhaps most important of all, how does one deal with factors that have nothing to do with evidence—financial interests, culture, values, politics—that support a medical practice?
For a cautionary example about how other factors can trump science, one need look no further than the debacle of high-dose chemotherapy and autologous bone marrow transplants for breast cancer. During the late 1980s, oncologists imagined they could treat advanced breast cancer by delivering extremely high doses of chemotherapy along with bone marrow transplants to mitigate toxicity. Dying women had no alternatives, and in the absence of any well-designed studies or controlled trials, experts insisted that such a regimen offered the only hope for patients. Insurers that refused to cover the $100,000-plus “experimental” treatments were successfully sued in court and pilloried in the press. It took a decade for government and private insurance companies to complete a series of definitive clinical trials that proved the procedure not only offered no benefit, but actually increased women’s risk of premature death. In the meantime, 20,000 women were treated at a cost of at least $2 billion. In this instance, the desire to do something for desperate patients combined with financial incentives for doctors and hospitals to push aside questions of evidence. Physicians who advocated this painful, ultimately useless, procedure, David Eddy remarked, “owe this country an apology.”
The need to improve the quality and cost of American medicine will drive the adoption of EBM. But resistance will be intense, which is easy to see from looking at areas where there are lots of high-quality data. One recent example: In May 2005, the U.S. Agency for Healthcare Research and Quality (AHRQ) published a comprehensive study of episiotomy (surgical resection of the skin between the vaginal opening and the anus). Obstetricians use this procedure in at least one-third of vaginal births in America, ostensibly to help their patents. But the AHRQ could find no evidence of clinical benefit, and much evidence of harms to mothers, from infection to incontinence. Unfortunately, anyone waiting for evidence that the AHRQ study has influenced obstetrics has been waiting in vain.
Perhaps the main obstacle to changing the current system is that it isn’t in most doctors’ interest to try to change it. Most episiotomies are done for the convenience of surgeons, who get out of the hospital faster and also bill for an extra procedure. As long as no major physician group or healthcare organization makes a dedicated effort to distinguish itself from the pack based on EBM, superior outcomes, and transparency, everyone has an economic incentive to provide services, regardless of benefit. More disturbing still, in purely economic terms, clinicians have real incentive not to know whether or not lucrative, albeit dubious, treatments work. The importance of fixing this broken system is widely acknowledged. Ultimately, doing so will require reinventing the medical information economy for the 21st century.
March 04, 2008
http://www.burrillreport.com/article-a_healthcare_gps_for_doctors.html