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Understanding Clinical trials > I want to learn about Clinical Trials

I want to learn about Clinical Trials

The following section was created using several sources of information considered as reliable and transferable for CDG. The goal is to improve the current understanding of clinical trials.




What is "health research”, “clinical research” or “medical research”?

When we talk about “health research”( sometimes also called “clinical research” or “medical research”) we are referring to all scientific studies and investigations that are done to improve human health’s knowledge. For instance, find a better or new way to prevent and treat diseases, test ideas or even answer questions about the disease or the treatment are some ways to do health research.

In population research, scientists (epidemiologists) study how and why diseases occur in populations, they look for some kind of pattern to find out why the disease in study occurs in some people but not in others. Watch the video prepared by Let's Learn Public Health available here . You can get a simple overview of the most common types of epidemiological studies, their advantages and disadvantages. 

Once scientists find the problem, they investigate it, and through laboratory research, they develop a possible solution and test it. Then, they finally test the possible solution for the initial problem on people, through clinical research. Figure 1 describes the Cycle of health research.  

Further reading: 

  • Cancer Council Australia has prepared the booklet called “Understanding Clinical Trials and Research” to help understanding more about clinical research.. Even knowing it was developed for other diseases,the previous concepts are well explained.. Read more here
  • The Harvard Countway Library Guide to Participating in Health Research offers a section to help you learning more about Participating in Health Research Studies




Why is health research important?

All we know about human health, diseases, cures and medicines today are due to all the investigation and health research that has been done through the years of human history. Clinical research is ongoing and behind every discovery, are thousands of people involved in the process, from health professionals and their patients to healthy people. The development of new medical treatments and cures would not happen without health research and the active role of research volunteers. Before health research, health professionals would choose medical treatments to cure their patients based on their guesses, which resulted in unsuccess, most of the time.  Nowadays, all treatments must be fully tested before doctors can prescribe them and that’s due to health research.




What are the different types of health research?

There are different types of health research (1):

Clinical research, also known as clinical trials, focuses on finding and testing new medicines (drugs), medical devices, or other medical treatments. Examples include:

  • Developing a new test for breast cancer
  • Comparing two medications (drugs) to treat heart disease to see which one works better
  • Developing lenses to help people see more clearly after eye surgery

Behavioural research looks at how people and groups act or behave in different ways. Examples include:

  • Answering questions about your experience with an illness
  • Taking part in a focus group to talk about a new way to improve health

Genetic research looks at the role of genes in different diseases and health conditions. Examples include:

  • The discovery of the BRCA gene mutation as a risk factor for breast cancer
  • Developing medications or treatments based on a person’s genes (this is also known as precision medicine)

Public health research focuses on the prevention and treatment of illness and disease in a community or population. Examples include:

  • Developing a media campaign to encourage people to eat healthily
  • Understanding how the flu spreads in a community

The Let’s learn public health created a video that looks at Public Health – the science and art of preventing disease, prolonging life, and promoting health through the organized efforts of society. You can watch it below.

A research registry is a collection of information about individuals. Many registries collect information about people who have a specific disease or condition, while others seek participants of varying health status who may be willing to participate in research about a particular disease. Individuals voluntarily provide information about themselves to these registries. Registries can be sponsored by a government agency, nonprofit organization, health care facility, or private company.

The International Federation of Clinical Chemistry and Laboratory Medicine (IFCC), made available an image that summarizes the different types of  “health research”( sometimes also called “clinical research” or “medical research”). Further reading here




What is a Clinical Trial?

Clinical trials are a kind of clinical research that involves people; they intend to test the effectiveness of a drug or if the clinical care strategy is working and if it’s better than those currently being used. Most drugs or medical procedures that are available for patients today went through clinical trial testing.

For further information: 

  • The Pancreas Patient has created an animation that explains what clinical trials are, how they are conducted, and why they are important for patients with diseases like pancreatic cancer. The animation also provides an overview of study design, eligibility criteria, informed consent, safeguards, different phases of clinical trials, and the potential benefits and potential risks of participation. Watch it now 

Different organizations have developed easy to understand content available and infographics devoted to explain what is a clinical trial that 

  • The University Hospital Southampton NHS Foundation Trust  created by an infographic that explains what is a clinical trial and the different phases. Download it here. 
  • The School of Business at George Washington University’s developed an infographic to show what’s involved in a clinical trial, why such trials are so important and what unique value they bring to patients in the below infographic: 




What kind of trials are there?

There are several different types of clinical trials which are described below (1):

  • Treatment trials test experimental treatments, new combinations of drugs, or new approaches to surgery or radiation therapy.
  • Prevention trials look for better ways to prevent disease or prevent a disease from returning. These approaches may include medicines, vaccines, vitamins, minerals, or lifestyle changes.
  • Natural history trials watch people over time to see which symptoms they have and how the symptoms of the disease change over time.  Natural history studies can be used to find out which symptoms of Duchenne are common and which are less common.
    For further reading watch the webinar dedicated to Natural history studies for rare diseases released by Findacure below.
  • Screening trials test the best way to detect certain diseases or health conditions.
  • Quality of life trials look for ways to improve the comfort and quality of life for people.
  • Genetic studies are designed to find the gene changes that cause a disease or symptom. These studies can also help provide information about how a gene works which can help researchers develop new ideas for treatments.




Why do we have Clinical Trials? Why are Clinical Trials so important? 

Although all new drugs, treatments and devices are rigorously tested in the laboratory they must also go through clinical trials so more can be found out about their potential benefits or risk. Clinical trials are the best way to compare different approaches to prevent and treat illness and health problems. Health professionals and patients need evidence from trials to know which treatments work best. Without trials, there is a risk that people could be given treatments that have no advantage, waste resources and might even be harmful. Many treatments that are now in common use in health care were tested in clinical trials (2). 
For further reading visit the clinical trials explained in plain english created by Cuttsy and Cuttsy here.




How do Clinical Trials work?

Medical researchers have dedicated themselves to this kind of research for many years, testing different options and ways to improve the patients’ condition, being essential to sequence the entire process in different phases and being resistive, things don’t always go well! The clinical trial process includes the preclinical and post-marketing, before and after the three phases of the trial itself, each phase has a different purpose and helps answer different questions.

Preclinical: Lab studies - Studies done in the lab to help determine whether a treatment is safe for studies in humans.
Phase 1: Small groups(≪100)- This is the first time a new medicine is tested in humans, usually carried out with a small group of people to determine a safe dosage.

Phase 2: Medium groups(±100)- Phase two trials test the new treatment on a larger group of people and it Tests if the treatment seems to be effective and looks for any side effects.

Phase 3: Large groups(≫100) - This phase is only carried out if the treatment has passed Phase one and two and involves a lot larger group of participants. The purpose of it remains the same as phase one and two, and may also compare the new treatment with the current standard treatment as an addiction.

Post-marketing (or phase 4): The last phase is carried out once a new treatment has passed all of the previous phases and has been approved by the regulatory authorities. Researchers use it to track a treatment’s safety and to find out more about a treatment’s risks or benefits and its optimal use. 

Mayo clinic has created an animation dedicated to the clinical trial journey and will help you understand the biomedical research pipeline. Watch it below. 

For further reading: 

  • The complex stories created an easy-to read explanation about the highly complex pathway for ushering new drugs from research, to development, to trial, to approval and fraught with challenges. See it here
  • Watch the video created by the National Cancer Institute  (NCI) What Are Clinical Trial Phases? to learn about the main phases of clinical trials.




How are Clinical Trials structured?

Each clinical trial has its own protocol that outlines every aspect of how the clinical trial is to be conducted, including: 

  • The reason for doing the trial; 
  • Who can join the trial (called “eligibility requirements,” or “inclusion criteria” and “exclusion criteria”); 
  • Possible benefits;
  • Risks and possible side effects; 
  • How long the study will last; 
  • What treatment is given, how the treatment is given, and how often the treatment is given (for studies of new treatments); 
  • What medical tests will be done to measure whether the treatment is working; 
  • What types of information will be collected about the patients taking part in the trial;


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Joana Grilo Sci and Volunteer Program Nova School of Science and Technology 2021. 


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Page modified at Wednesday, April 28, 2021 - 13:36