How Science and Medicine Change: Antibiotic Stewardship Provides an Example of the Process
The psychological reasons that determine why people have difficulty changing their minds is a topic of great interest to us at Critica. Once a belief is held for a long time, deep-seated processes in the mind attempt to ensure that the belief is resistant to alteration, even to the point of accepting incorrect information if it seems to confirm what is believed.
Science, including the science underlying medical practice, is supposed to be self-correcting so that when something turns out to be incorrect there is a natural process for change that brings about a move to a more appropriate position. But scientists and doctors are hardly immune to the processes that entrench incorrect beliefs and make them hard to dislodge. Witness this opening to a paper published in a medical journal last January:
The millennia-long annals of medical history are replete with placebos or poisons that doctors administered ad libitum, based on limited or no data, often to the overt detriment of patients. Snake oil, mercurous compounds, arsenicals, and purgative bleeding dominated the practice of medicine for centuries.
Authored by a distinguished group of infectious disease experts, this paper highlights examples of medical dogma that were slow to change. “While all fields of medicine contain elements of practice based on tradition and lore, few are more afflicted than Infectious Diseases,” the article goes on to say. The authors point out that antibiotics were developed before doing randomized controlled trials (RCTs) became normative throughout medicine to document the safety and efficacy of medicines. By the time RCTs rose to gold standard status, many approaches for the use of antibiotics had already been reified in practice, making them difficult to change even as new evidence emerged. “The question now becomes, can the field of infectious diseases overcome the inertia of our past?” they ask.
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Adoption of New Science By Medicine Can Be Slow
While the willingness to be this self-critical of their field is admirable and does exemplify one aspect of the science of medicine—its periodic attempt at self-correction—the article also highlights the fact that protocols in medicine can become just as fixed and rigid as many other beliefs people have. As Kusha Davar and co-authors explain, from the first administration of an antibiotic in 1931 through the introduction of penicillin in the 1940s, antibiotics proved remarkably effective at treating even life-threatening infectious diseases. Two things often went unevaluated by formal studies, however: how long to give antibiotics and by what route.
As surprising as it might sound, until recently there was little evidence from controlled clinical trials to determine how long an antibiotic should be administered. When a doctor tells a patient to take an antibiotic for a sinus infection for 10 days in order to be sure that the “bacteria '' are all truly eradicated, for example, that instruction is based more on lore than science. We rarely know if sinus infections are indeed bacterial versus viral (the latter of which do not respond to antibiotics) in the first place and whether it takes 5 days or 12 days to treat a bacterial sinus infection is unclear even today. The very notion that longer duration of treatment is important to get a complete eradication is also questionable: we do know today that the longer bacteria are exposed to antibiotics the more opportunity they have to mutate to antibiotic-resistant forms. Thus “longer is better” is not always the case when it comes to duration of antibiotic treatment. “When considered from this perspective,” Davar et al posit, “one would think that a relatively small number of modern, high-quality, randomized controlled trials might be sufficient to change practitioner behavior away from historical norms and toward evidence-based, optimal durations of antimicrobial therapy.” Alas, practitioners have been slow to accept that shorter durations of antibiotic treatment for common bacterial infections might not only be adequate but safer.
Are Oral Antibiotics Sufficient for Life-Threatening Infections?
When it comes to the route of administration for antibiotics, the article points out that once again belief and tradition are the basis for common practice rather than the results of formal scientific inquiry. For many serious infections, it is considered absolutely required that antibiotics be given intravenously rather than by intramuscular injection or by mouth. Examples arebone (osteomyelitis) and the heart (endocarditis) infections. But once again the authors of the perspectives paper note that: “No prospective study ever established IV [intravenous] antimicrobial therapy as more effective than oral therapy for the treatment of osteomyelitis or endocarditis.” In fact, with the advent of modern antibiotics that achieve high blood levels with oral administration, there is now adequate evidence that many such infections can be treated with medications given by mouth. Yet, the switch from intravenous to oral antibiotics when appropriate has been a very slow process. Doctors believe that serious infections need serious interventions and giving medicine intravenously just seems like the right thing to do in these instances.
It is often said that it takes an average of 17 years for new findings to be translated into clinical practice, although even that number is the subject of debate among scholars. There is widespread agreement that whatever the exact number of years it takes, the lag between scientific progress and practitioner adoption takes too long, especially now that information about new studies is so rapidly disseminated. “Arguably,” Davar and colleagues write, “it is to the detriment of patient care that the findings of numerous, concordant randomized controlled trials are not adopted into practice due to existing limitations, particularly in circumstances where actual practice is based on no evidence at all. Delay in changing practice after new data are published is not unique [to] infectious diseases. The entire field of medicine faces this challenge.”
Protocols for the treatment of illnesses should derive whenever possible from RCTs. Sometimes, a new RCT will contradict the findings of older RCTs and experts must grapple with whether the new work is sufficient to overturn previous practice. When it is not possible to conduct RCTs, experts must decide if observational studies are adequate to make adjustments in clinical algorithms. In most cases, experts will insist that any finding, even when it derives from a rigorously conducted RCT, be replicated by other studies before agreeing to change clinical guidelines. When it works, science follows a natural progression of accumulated studies that ultimately result in the creation of consensus and then practice guidelines and algorithms.
What Davar et al are talking about in their article, however, is quite different from the situation in which studies disagree with each other and a new consensus is required. In the cases of how long to administer antibiotics and by what route their contention is that practice is largely based on tradition rather than on the science. In some cases, no studies exist to answer a fundamental question but in many other situations the available evidence is not being converted into clinical practice because physicians are rooted in those traditions and resistant to accepting the changes that new science requires.
The idea that a disease like bacterial endocarditis could be treated with oral antibiotics will be shocking to many physicians and that helps to explain why in this case new evidence takes so long to translate into clinical practice. Davar and colleagues’ point is that the case of how long and by which route to administer antibiotics are examples of a more widespread problem in the practice of infectious disease medicine and other medical specialties. Although making decisions about how to treat illnesses like a serious heart infection exceeds the capacity of all but a small group of experts, no one should ever hesitate to ask the question “what is the evidence for that” whenever a recommendation is made. We may be surprised to learn that the evidence is paltry or even non-existent. That should prompt a serious conversation about the basis for the recommendation and what is the best way to proceed.