Evidence-based medicine: What it is and why we are often treated incorrectly
The increasingly common phrase "evidence-based medicine" It is puzzling for many: it would seem impossible to prove, because medicine is a science, and in science any practical methods are necessarily based on the results of research confirming their expediency. Moreover, in the case of the same disease, doctors often offer completely different, if not opposite, forms of examination and treatment methods. We live in a time of unprecedented scientific progress, but very often doctors put false scientific diagnoses like vegetative-vascular dystonia to desperate patients and prescribe calf-based homeopathic medicines.
Sometimes treatment resembles something in between a lottery and a wandering maze, and each subsequent visit to the doctor instead of answers raises new questions. Ahmed Rustamov, a general practitioner and the founder of a popular science project about the principles of evidence-based medicine Medspecial, told us why the principles of evidence-based medicine are not used everywhere and what is a possible way out for doctors and patients.
What it is
Up to the second half of the twentieth century, doctors around the world relied solely on the personal experience and opinions of more experienced physicians in matters of diagnosis and therapy, but this did not guarantee a favorable outcome, and sometimes did lead to dire consequences - for example, at the beginning of the last century for treatment mental disorders, teeth were removed, and heroin produced by the Bayer brand was recommended for children as a means of coughing and painkillers.
The current situation did not satisfy either the doctors or the patients, and in the 70s of the twentieth century a new approach to diagnosis and treatment, called critical, was proposed. Now, before applying this or that method of diagnosis or treatment, it is necessary to have evidence of the effectiveness of the method used: the intervention offered to the patient must represent the greatest efficacy and the least risk. This approach, called evidence based medicine in foreign literature (medicine based on proven), and evidence-based medicine in Russian-language literature, is today the gold standard throughout the world.
Nevertheless, in Russian hospitals, many doctors do not adhere to the principles of evidence-based medicine and are still working according to outdated standards, while in medical schools they are still taught using Soviet textbooks. Surprisingly, but a fact: a significant part of drugs and methods of treatment do not comply with the principles of evidence-based medicine, their effectiveness has not been proven accordingly.
What are the principles of evidence-based medicine
First of all, it should be understood that evidence-based medicine is not a branch of medicine. This is nothing more than a tool - figuratively speaking, a ruler. There is a certain set of rules for conducting medical research, which was finally formed by the beginning of the 80s of the twentieth century and which is still followed in world practice.
In modern medicine there are international standards Good Medical Practice (good medical practice), Good Clinical Practice (good clinical practice), Good Laboratory Practice (good laboratory practice). If we take out the questions of ethics and organization of practice indicated in them and speak only about modern medical research, it can be argued that they fully reflect the principles of evidence-based medicine. These studies can mathematically compare one method of treatment or diagnosis with another, or, if there is no other method, to date, with placebo.
The origins of evidence-based medicine can be sought just in the placebo effect, that is, the pacifier, devoid of the active ingredient. The average placebo effect in mentally healthy people can reach 30%. In people who are commonly called suggestible in the common people — that is, both highly sensitive and anxious disorders — the placebo effect can reach 60%. An ordinary medical practitioner cannot always understand whether the treatment prescribed to them helped the patient or the body recovered itself, as it happens, say, during a cold. Evidence-based medicine is a tool that allows you to compare different medical procedures and determine their degree of effectiveness.
Who and how determines the effectiveness of treatment
Evidence is of different orders. A classic example of ambiguous methods is the dilemma "To treat or not treat the flu?". More recently, all doctors were unanimous in a positive response, but recent data suggest that treatment is not very necessary. Now a number of antiviral drugs like Tamiflu are used for it, but studies have shown that this drug reduces the duration of the disease by literally 2-3 days, without reducing the risks of secondary viral complications, such as a bacterial infection. Now Tamiflu is recommended mainly in difficult cases. After all, when a doctor prescribes a drug, he must soberly evaluate the risk-benefit ratio, and this ratio in the case of flu treatment raises big questions.
In modern medicine, there is the concept of "hierarchy of evidence", it is divided into two aspects: the level of evidence and the class of recommendations. There are only three levels of evidence - A, B and C. The highest level A is assigned to the type of medical intervention, if the data testifying in its favor were obtained in the course of several, usually large, randomized studies - they are the gold standard for obtaining scientific data on new diagnostic methods. or treatment. In such studies, patients are divided into three groups: a test, in which they will test a new drug, a traditional one, in which the treatment of this disease occurs in a conventional manner, and a control one, in which placebo is used.
Studies of this type are called randomized because the decision about which group the patient falls into is made in a completely random manner. The blinding method plays an important role here: it is that the patient taking a placebo does not know what it really is - a dummy or a working drug. A double-blinding method is highly effective, when the doctor who monitors the patient’s dynamics also does not know which group this or that person is in, and then the other doctor who has this data analyzes the result.
In the US, there is no such thing as unproven medicine at the official level.
If data on medical intervention are obtained in a small number of randomized trials, in non-randomized trials or in a number of clinical observations, they are assigned a level of evidence of B. This refers to Tamiflu. Level C is the lowest and means that medical advice is based mainly on expert opinion. It must be said that in the USSR the level of evidence C from the category of “the chief said” has always been considered more than sufficient and is still often raised to the highest rank in Russia and many CIS countries.
Now about classes of recommendations. This classification is based on the degree of agreement of specialists in terms of the benefits and effectiveness of the treatment method. Class I assumes reliable evidence based on randomized trials and experts agree that the treatment is appropriate. For example, the statement that aspirin lowers the temperature is A I, that is, the class of recommendations I at the level of evidence A. When experts' opinions on the benefits or effectiveness of the procedure or type of treatment differ, this is the level of recommendations II. If most of the evidence or opinions of experts speak about the benefits of the treatment method, it is classified as class IIa, but if a smaller amount is in favor, the class IIb is assigned to the method, and this means that this type of medical intervention is more harmful than useful.
Decision on the degree of evidence is handled by special expert bodies: the World Health Organization, the Cochrane Collaboration, the Society for Critical Care Medicine, the British Medical Journal, and many others. The same organizations create guidelines - guidelines for doctors. Such medical recommendations are based on the most reliable scientific evidence, and the stronger the evidence, the better the guideline for practicing physicians will be.
Why evidence-based medicine is not common in Russia
Medical strategies in the world differ significantly. For example, in the United States at the official level there is no such thing as unproven medicine. The US Food and Drug Administration (FDA) has a very tight control on this part and does not allow drugs to the market without reliable evidence of their benefits. In Europe, things are somewhat simpler. This is clearly illustrated by the story of the drug "Preductal", which is used in the treatment of coronary heart disease. A lot of expensive studies of this remedy were carried out, and as a result it was proved that Preductal does not reduce the risk of developing heart attack and stroke and is mainly shown to people who need heart surgery and who for some reason do not want it. In the US, the drug was never missed, and in Europe it was included in clinical recommendations for some time.
In Russia, the situation is much more complicated, the same can be said about most of the countries of the former USSR. Of course, this does not apply to Latvia, Lithuania and Estonia - in the European Union countries an appropriate level of supervision over the quality of medicines is provided. In Georgia, things are also better - under the presidency of Mikhail Saakashvili, a number of important changes in the field of health care were implemented there, and now there is obvious progress in the application of modern methods, although on the issue of accessibility everything is not so simple. However, it is always a double-edged sword: in the health system of any country, there are constant attempts to balance between quality and affordable. Judging by the testimony of colleagues from Armenia, it seems that evidence-based medicine is also used there a little more actively than in Russia.
Everything is clear with the countries of the former USSR: until 1990, the exchange of scientific data was limited, and our health ministries lined up the entire system on the basis of the rule of Soviet science. Today, when the exchange of information has become possible, leaves much to be desired funding in the field of medicine. At the same time, in matters of evidence-based medicine in Russia, everything is quite good with cardiology (this is due to Yevgeny Ivanovich Chazov) and with endocrinology - Ivan Ivanovich Dedov and Galina Afanasyevna Melnichenko successfully promote modern methods of diagnosis and treatment.
About 20% of Russian doctors follow the principles of evidence-based medicine, and this is a very optimistic figure.
Unfortunately, there are few such islands, and for the most part Russian medicine is not evidence-based. The principles of evidence-based medicine are followed by about 20% of doctors in Russia, and this is a very optimistic figure (of course, we are talking about big cities, and in the regions the figures are much lower). In order for all of us to be calm for domestic health care, this figure should be at least 75%. The root of the problem should be sought in the medical education system. If before the third year in medical schools, things are relatively well, since the general disciplines (anatomy, physiology, pathophysiology) are studied, then problems begin - mainly because students are not taught to collect and analyze information. If a modern physician does not have adequate knowledge of statistics in general and does not delve into particular medical statistics, it is difficult for him to assess the quality and results of modern research.
That is why, even if a super minister of health emerges in the country who will do everything right, a significant improvement in the overall picture can be expected only in about thirty years. After all, if today to completely change the system of medical education, there should be a sufficient number of qualified graduates of medical institutions. In addition, it is necessary to completely revise the postgraduate education system. Of course, you can make doctors go to international conferences, you can organize master classes of famous doctors, but until every doctor understands what and why he does, nothing will change.
There is a very simple example. Some medications that are prescribed for coronary heart disease do not affect the patient's general well-being, but reduce the risk of myocardial infarction. Those doctors who are proficient in evaluating evidence-based medicine may not see results when prescribing a particular drug, but understand that these results are there, since a number of scientific studies clearly show this.
Why Doctors Prescribe Ineffective Drugs
In Russia, there is a specific situation with the certification of drugs. Anyone, even the most effective brand-name drug that has undergone all sorts of randomized studies and is certified internationally, will have to undergo Russian certification before entering the Russian market. There are no significant reasons for this, and now there is a question about the abolition of this condition, but so far everything is at the level of discussion.
As for Russian drugs, they do not pass any international certification, since there is no task to bring them to the world market. By our own laws, double glare or randomized studies are optional. Thus, drugs like "Arbidol", "Kagocel" or "Amixin" are produced absolutely legally and are widely prescribed by doctors, although no evidence of their usefulness has been found in the course of the relevant studies. These medicines take the first places in the statistics of the best-selling drugs in Russia. In addition to them, there is a variety of unthinkable homeopathy in the top, such as "Canephron" based on centaury grass and lovage powder or Actovegin, the active ingredient of which is an extract from the blood of calves. In turn, in the US, the best-selling drugs are statins, serious drugs that save people from myocardial infarction and stroke and prolong their life.
How to check whether the prescription is based on the principles of evidence-based medicine
The law "On the basis of the protection of public health in the Russian Federation" clearly states that the patient makes the final decision on treatment. If the doctor prescribes "Arbidol" and the patient believes that this tool is ineffective, he is unlikely to use it. True, the same law obliges the doctor to reasonably justify a particular appointment to the patient. Unfortunately, this law is not always respected, like many good laws.
For the average unenlightened patient, finding a clinic or doctor in Russia that follows the principles of evidence-based medicine is not easy — just as it’s not easy to figure out the doctor’s prescription. How to determine whether this appointment is adequate? First of all, one should not doubt the doctor’s diagnosis - certainly, if this diagnosis is recognized by modern medicine. If you are diagnosed with vascular dystonia or dysbiosis, then you should look for a second expert opinion. Nevertheless, even if the doctor makes, conditionally speaking, a non-existent diagnosis, this does not mean that you should immediately run away from such a doctor.
In some cases, the doctor, using the above incorrect terms, can explain to the patient what is actually happening to him. If the doctor makes you a diagnosis of vegetative dystonia and at the same time informs you that it would not hurt to consult with a psychotherapist, this is quite a normal specialist, and if you are prescribed a dozen questionable drugs for the same diagnosis, then it is a reason to seriously think about changing a doctor.
If the diagnosis is generally adequate, attention should be paid to what the treatment consists of and whether the effectiveness of the prescribed drugs is proven by scientific research. Patients who speak English will benefit from checking any prescribed drug on the FDA website, and if it is not there, whether it is necessary to use this tool is a big question.
What should be considered for the patient at the stage of diagnosis
For an adequate use of medical prescriptions, it is important to know one more thing: in cases with a number of diseases, it is enough for the doctor to establish a diagnosis in order to act according to a certain algorithm, and subsequent patient complaints will no longer be of importance to him (however, a good specialist will try to listen to them with understanding). Forty-minute consultation is not always necessary in order to diagnose bronchitis. Тем не менее в подобных случаях пациенты часто думают, что доктора ими пренебрегают и не оказывают им должного внимания. Особенно часто такое недопонимание случается в государственных клиниках, где врачи ограничены временем приёма.
На этапе постановки диагноза немаловажна последовательность диагностических тестов. Классический пример - назначение магнитно-резонансной томографии (МРТ) при любых жалобах на боль в голове. In the structure of methods of work with patients with headache, MRI takes the 258th place, therefore the doctor, who is without any reason prescribing this diagnostic method, most likely is not sufficiently qualified. At the same time here, as elsewhere, there are exceptions: for example, the patient came to the reception with a headache, the doctor saw his neurological loss, suspected a brain tumor and, based on the results of the examination, appointed an MRI. In this case, medical intervention is quite adequate.
In Russian medicine, far more desperate diagnostic methods are common. Sometimes quite serious doctors resort to various medical heresies, such as the Voll diagnosis based on the results of measuring the electrical resistance of the skin on the fingers and toes. From the point of view of modern evidence-based medicine, this method lacks any diagnostic capabilities, and it does not have stable data from clinical studies. Therefore, the Voll method, which does not have scientific foundations, is not recognized by the scientific community, and it is better to run away from such quackery.
In order to assess the feasibility of prescribing a particular examination, there is a simple question that the doctor can ask himself, and the patient, respectively, the doctor: "What will I do if the result is positive, and what will I do if the result is negative ? " If the answers to these two questions are the same, then this survey is not necessary.
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