Glossary
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Clinical research is divided into two broad categories: observational studies and interventional clinical trials. Both types are conducted on humans.
Observational Studies
As the name suggests, observational studies observe and gather information on humans in order to advance health knowledge. They look at human behaviour, analyze health data, and so on. For example, observational studies can be used to better understand a medical condition or find out if people are following their usual treatment properly. No new medications are given, and no intervention occurs during an observational study.
Observational studies are usually conducted in an academic setting in collaboration with specialized medical teams from the health network. These studies make it possible, among other things, to draw conclusions about the causes and risk factors of a specific disease or medical condition.
Three types of observational studies
Case-control studies
These studies compare a “case” group with a specific disease and a “control” group with no disease. The goal is to discover the risk factor(s) for the disease. The research team knows which group of participants presents with the disease and analyzes their exposure to various factors that may have increased their risk of having the disease.
Cohort studies
These studies compare two or more groups (cohorts) that are as similar as possible. However, the groups differ in that one presents with a risk factor, whereas the other does not. The goal is to associate the risk factor in question with the likelihood that a disease will occur.
There are two subtypes of cohort studies:
- Retrospective cohort studies analyze the history of participants with a disease to understand the risk factors that may have caused it.
- Prospective cohort studies follow groups that do not have a specific disease for a period of time to see how certain risk factors influence the likelihood that a disease will occur.
Cross-sectional studies
These studies collect health data on a large group of people at a given point in time. For example, they can be used to analyze the frequency of occurrence of a given disease or to identify the people most affected by a given medical condition. They can then draw conclusions that would explain these observations.
Interventional Clinical Trials
Clinical trials, also known as interventional clinical trials, are primarily used to test health innovations on humans. These innovations may include new drugs or enhanced version of an existing drug, biologics, medical devices, diagnostic tools, vaccines or new surgical procedures. They are used to test the efficacy and safety of the innovation, and to measure its undesirable or unexpected effects on human beings. In medical research, this step is essential in demonstrating the usefulness of any health innovation.
Clinical trials are typically carried out in three phases. A fourth phase can sometimes be conducted after the innovation has been approved. Each successive phase has a specific purpose. Together, they provide different ways to prove that the study treatment is effective and safe for humans. With the proofs obtained during phases I to III, the sponsor can apply for government approval to make the treatment available to the public.
Before any clinical trial project begins, it goes through a strict approval process carried out by Health Canada, and by various scientific, medical and ethics committees.
Five broad categories of clinical trials
Treatment clinical trials
They test new treatments or ways to make existing ones more effective.
Prevention clinical trials
They look at new ways to lower the risk of developing a disease or to stop the disease from coming back.
Screening clinical trials
They look for ways to find a disease in its early stages, before people have symptoms.
Diagnostic clinical trials
They help find better ways to diagnose a medical condition or determine its specificities.
Supportive care clinical trials
They look at ways to improve the comfort and quality of life of people with a specific medical condition.
Real-World Evidence (RWE): A Type of Combined Clinical Research
Real-World Evidence (RWE) plays an important role in collecting rigorous medical information and data regarding the use, benefits and potential risks of a new treatment in the context of its routine use in a specific health system.
Real-world evidence is needed to improve clinical research, namely to gather knowledge, improve the conduct of clinical trials, ensure patient safety and support regulatory decision-making.
Real world studies can be observational or interventional, with the data collected from these studies coming from daily clinical practice or routine healthcare management. Real-world data can originate from various sources, such as health records, patient registries, electronic medical records, private or public insurance schemes, portable devices or other biosensors, as well as directly from people living with a medical condition. These studies are evaluated by healthcare institutions and ethics boards in terms of compliance, data management and individual safety.
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