The enthusiasm of some doctors it's from part of the Brazilian population with the use of drugs with no proven utility against the new coronavirus, it has become clear that there is still a long way to go before the so-called evidence-based medicine is consolidated in the country.
This approach, which seeks to use the best available scientific data to support decisions about the treatment of each patient, has been left aside when health professionals and managers choose to employ medications like hydroxychloroquine Or the ivermectin, whose effectiveness and safety have not yet been demonstrated.
“Instead of evidence-based medicine, we see some practicing impression-based medicine,” says biologist Natalia Pasternak, president of the Instituto Questão de Ciência (association dedicated to the defense of public policies based on scientific data). "It seems that we are failing to try to teach scientific method in courses in medicine, nursing and others in the health field."
Although attempts to test treatments scientifically have occurred since the 17th and 18th centuries, the proposal to systematize these tests as a guide to medical practice is quite recent, dating back to the 1980s and 1990s, when the term “evidence-based medicine” was used for the first time by researchers like Gordon Guyatt, from McMaster University (Canada).
The intention was to increase the objectivity of clinical decisions based on the knowledge obtained, for example, in multiple studies with a large number of patients to recommend or not a specific therapy.
To reinforce the reliability of these recommendations, such studies should adhere to standards such as the existence of control groups (that is, the division of the studied patients into at least two groups, one of which received the treatment being tested, while the other received a treatment. standard previously used or an innocuous substance, for example) and the so-called randomization (allocating patients to different groups at random).
Such approaches are necessary to reduce the different biases that arise naturally during the observation of a treatment. Many health problems, for example, end up improving thanks to the patients' own organisms, but the lack of a control group could lead doctors to mistakenly assume that the treatment was responsible for the improvement.
In Brazil, training courses for health professionals that include subjects specifically dedicated to teaching these concepts are still rare.
“In the case of medical schools, there is often only one module on the subject in the discipline of epidemiology, for example,” says rheumatologist Rachel Riera, from Hospital Sírio-Libanês and Unifesp (Federal University of São Paulo), where she minister just one of those rare disciplines. “There are also many sporadic and other graduate courses, which have grown.”
For Riera, evidence-based medicine is not opposed to the personal experience of each doctor when dealing with his patients on a daily basis, but it helps to prevent certain treatments from continuing to be used uncritically out of habit, without bringing real benefits to the patient. treatment.
She cites the example of patients with severe burns, who, in general, can die from two causes: wound infections or hypovolemic shock (severe decrease in blood volume). For many years, one of the treatments prescribed to deal with hypovolemic shock was the use of the protein albumin in the serum of these patients, to increase blood pressure.
“It was something that seemed to make sense, but it was based on small-scale observational studies,” explains the doctor. Broader data, under more controlled conditions, revealed that, in addition to being more expensive, the procedure with albumin led to more deaths than the simple use of saline.
“It is clear that there is a big gap, often, between what would be the best possible solution and the context of each health professional and each patient. Treating an acute myocardial infarction will never be the same in a hospital in a large city and in a riverside community in the Amazon ”, she ponders. "It is no use just focusing on the results of large studies if you do not take this into account."
Riera also says that no recent situation can be compared to the Covid-19 pandemic, when considering the need to learn very quickly ways to face a new disease.
For experts, however, the challenge's originality does not mean that any treatment recommendation is equally valid.
"There is a brutal difference between the individual position of scientists and doctors, which is legitimate, and what is consensus on a given issue", explains biochemist Hernan Chaimovich Guralnik, from USP's Institute of Chemistry.
He compares the debate over unproven treatments against Covid-19 to the issue of climate change. “The individual opinion of a researcher may even be respectable in his field of knowledge, but the IPCC (UN panel on the climate) tries to be guided by a global consensus when analyzing the theme. Of course, consensus can also change, but that only happens when a lot of new evidence contradicts an existing consensus. ”
Natalia Pasternak remembers that the seal of SUS (Unified Health System) to the use of dozens of alternative health practices without scientific evidence, such as homeopathy, is another indication of how the debate on evidence-based medicine is still in its infancy in Brazil. “This lack of rationality was already confirmed, in the end, but it had never affected an emergency context as deeply as now.”
"Human beings are irrational in nature, which means that understanding irrational behavior is not difficult," Gordon Guyatt told Folha. "But if it was to choose an untested drug to use, the evidence would suggest that several others are a better bet than hydroxychloroquine."