How can I be sure that the recommendations I receive after a medical consultation are correct? In the article below, we discuss evidence-based medicine.
Sooner or later, each of us and those close to us find ourselves in need of a medical consultation, and this question will need to be answered. We live in a world where information flows freely from various sources, we hear about side effects from other patients, and we wonder if we are safe following a certain medical, interventional or surgical treatment.
I will try to answer these legitimate questions by revealing the process behind the doctor’s recommendations following a medical consultation. Each doctor relies on their experience and the results they have had in treating patients with the same disease, but all take into account the same saying: “There are no diseases, but sick people”, which means that each of us is unique and, as patients, we are different from someone else who has the same suffering.
But beyond the experience of each doctor, there is now a strong emphasis on the concept of evidence-based medicine, which refers to patient care based on the best and clearest evidence from medical research used as guidelines for clinical decision making.
Clinical trials are essential for evidence-based medicine
For the development of evidence-based medicine, clinical trials are essential. That is why a brief presentation of what a clinical study is, is useful.
According to the American Cancer Society, clinical trials are studies that test new drugs, already approved drugs, medical devices, and other forms of treatment. Some clinical trials are looking for new ways to detect, diagnose or measure the spread of certain diseases. Clinical trials are conducted in several phases, each addressing a certain question.
Clinical trial phases are also applied in the development of Covid-19 vaccines
Phase 0, which is not necessary for all clinical trials, attempts to answer the question of whether and how the new drug works. Very small doses of the medicine are used in a limited number of people (often less than 15) for a short period of time.
Phase I determines the safety of the treatment, aiming to find dosages that are safe and have no side effects. Even if the drug has previously undergone laboratory and animal testing, in order to reduce the risk of side effects, in this phase, its action in humans is investigated. Here too, the sample of patients is small and the dose is gradually increased, with patient safety being a priority.
Phase II determines if the treatment is effective, using the dosages and methods of the previous phase on a larger sample of patients. Inactive treatment (a placebo) is not used in these early stages.
If the treatment is effective, phase III follows, and it will have to determine whether the new drug is better than existing treatments, comparing the efficacy and safety of the new substance with the standard treatment. Patients who meet the inclusion criteria are randomly selected (hence the name of “randomized” studies) to receive either standard treatment and the new drug, or standard treatment and a placebo (which looks identical). Neither the patients nor the treating physicians know which treatment contains the new drug or the placebo, hence the name “double blind study”.
Phase III clinical trials include more patients (hundreds, or even thousands) and are conducted in multiple centres/hospitals from several countries. The patients are closely monitored, and the study, which lasts longer (for years) in phase III than in the previous phases, can be halted prematurely in case of frequent side effects or when the efficacy of the new treatment is evident, in order to expedite its administration.
If in phase III it results that the drug is effective and safe, the process for its approval begins at the competent forum, which in the US is the FDA (Food and Drug Administration) and in Europe the EMA (European Medicines Agency).
In phase IV, an already approved drug is monitored for a longer period to evaluate its effects and safety on thousands of patients. Clinical trials, far from being “human experiments”, represent a breakthrough in medical research, allowing the introduction into medical practice of drugs or procedures that save or prolong lives.
How medical guidelines are made
In Europe, medical professionals in each speciality belong to a specialized society in the country in which they work (for example, the Romanian Society of Cardiology), which in turn is included in a European society that includes all national societies in Europe (for example the ESC: European Society of Cardiology). Every few years, the ECS issues guidelines for various diseases in each speciality (guidelines on myocardial infarction, hypertension, atrial fibrillation, etc.). These guidelines are written by teams of dozens of reputable specialists with training in the disease. The purpose of the guidelines is to facilitate the medical decision, while offering the possibility of an integrated medical practice, regardless of the country.
Each guideline contains different classes of recommendations, with different levels of evidence, which professionals must take into account in their practice.
Thus, class I recommends a treatment or a procedure as a beneficial and effective one (for example, the administration of aspirin in acute myocardial infarction). Class II recommendations contain divergent views on the efficacy or usefulness of a treatment or a procedure and are divided into classes IIa, where the evidence is predominantly in favour of the drug, and IIb, where the treatment can still be administered with caution in certain situations. Class III does not recommend the medicine or procedure. Thus, in current practice, doctors will always use drugs in class I and IIa, those in class IIb only under specific conditions, and never those in class III.
Obviously, the guidelines are not a substitute for the professional’s judgment but are meant to be a helping hand in an age when advances in medicine are made at a dizzying pace, with evidence-based medicine providing greater efficiency and safety in diagnosing and treating a multitude of diseases.
I would like readers who go through this short and probably incomplete presentation to have more trust in today’s medicine, in the hope that God will take care of each of us and use medical professionals to alleviate human suffering.
Professor Constantin Militaru, PhD, is a primary care cardiologist, MD–PhD, Associate Professor at the University of Medicine and Pharmacy of Craiova, member of the European Society of Cardiology and the American College of Cardiology.