What is a clinical trial?
Clinical trials are a form of research that involves humans, including patients and non-patients. This research looks at medical interventions, from new drugs and devices to surgical procedures, that are designed to prevent, identify, treat or control a range of diseases and conditions.
In Australia and around the world, clinical trials are an important tool that researchers use to understand and improve people’s health and well-being. They can determine if a new treatment or technique is safe, effective, and a better option than the currently available standard of care.
If you are researching or undertaking clinical trials, there is a lot of information to absorb. Let’s quickly overview the basics, including why we have clinical trials, how they are designed, and some key steps involved.
What is a clinical trial?: A quick summary
- clinical trials refer to research involving humans
- clinical trials aim to help people and contribute to the safe and effective use of new medical technology and treatments
- there are different types of phases within a standard trial – there are four key phases to a clinical trial
- every trial has a unique design – such as controlled, randomised or blind trials.
Read on to learn about clinical trials in more detail.
Why do we need clinical trials?
In 2022, the clinical trials sector generated $1.6 billion for the Australian economy; during this year, 1,850 trials started and around 90,000 Australians participated, according to figures from MTPConnect.
Clinical trials have multiple benefits for our health and medical system, related research industries, and the Australian population and economy.
Here are some key reasons why they are important.
They help people
Clinical trials aid the development of new medical interventions that can reduce pain and disease, help people manage disability or chronic health conditions, and improve the length and quality of human life.
These interventions may include a new drug or medicine, vaccine, medical device or surgical technique. They may also relate to preventative care, behavioural treatments, or other advances in health services.
Past clinical trials have helped develop a range of game-changing treatments for conditions including heart disease, cancer and asthma.
They strengthen testing procedures
Before a new intervention is tested in a clinical trial, scientists perform a range of laboratory tests or studies, usually involving animals.
However, these tests provide a limited picture of how this intervention may work with humans. Clinical teams build on this previous research with trials that exclusively involve living people. This is the primary way they can gauge the safety and effectiveness of a new treatment, technique or tool.
They use large groups for consistency
Clinical trials also provide the advantage of testing on a large group of people rather than on small groups or individuals. This approach ensures an intervention will produce consistent results.
They set a high standard for patient care
Overall, clinical trials often set a high standard for health research and treatment. Australian clinical trials have been recognised internationally for their high quality of patient care.
Who is involved in clinical trials?
Clinical trials involve a wide range of people both across and outside of the medical profession. Four key groups to consider are the research participants, research team, sponsors, and other relevant authorities.
The participants
Before a clinical trial begins, the research team will select specific types of people to participate in line with their goals. There will be certain factors, known as inclusion and exclusion criteria, that determine the eligibility of participants.
These participants may be healthy volunteers or patients, typically with the disease or condition the new intervention is designed to treat. They tend to find out about trials through their General Practitioner (GP) or advertising. Their participation is voluntary, and they must give their informed consent. Participants will sign up for a wide range of reasons, including a desire to assist medical research, to help others, or to receive a new treatment.
Overall, it is important that clinical research reflects the diversity of the wider population. This research will involve people of all ages, genders, and sexualities, as well as from different racial, cultural, and economic backgrounds.
The research team
The research team will involve a range of roles, including, most obviously, the trial researchers and investigators, as well as coordinators and monitors. These roles are typically occupied by a range of people within the medical profession, from both clinical and non-clinical settings.
The organisations they work for include hospitals, universities, specialised medical clinics or research institutions, or pharmaceutical, biotechnology or medical device companies. They may be doctors, nurses, pharmacists, pathologists, radiologists, biostatisticians, or research assistants.
The main person overseeing the conduct of a trial on-site is known as the primary or principal investigator.
The funder
Outside of the research team, key personnel that help get clinical trials off the group are the groups or individuals providing financial support and sponsorship. This funding will help determine if a clinical trial is either an industry-led trial or investigator-led trial.
If a clinical trial is initiated by the industry, it is financially supported by a commercial entity. Often, this will be a pharmaceutical, biotechnical or medical device company wanting to test a new drug or device. They will cover any associated costs, including the salaries of the researchers.
Investigator-led trials, also known as investigator-initiated trials, are not sponsored or initiated by these commercial entities. They are usually undertaken by health institutions or within an academic setting and funded through grants or sponsorship from government agencies or departments, research groups, foundations or charities.
Other relevant authorities
In addition to the research participants, clinical team and funders, clinical trials require approval or involvement from a number of other authorities.
These authorities include the institutions or organisations that provide a location for the trial, from hospitals and treatment centres to universities, and the Human Research Ethics Committee (HREC) that ensures the trial meets ethical standards and guidelines.
Clinical trial types
In Australia, the main types of clinical trials are treatment trials, screening or diagnostic trials, and prevention trials.
Treatment trials
Treatment trials test new medicines, treatments, medical devices, surgery techniques, and both medical and non-medical therapies. They may also test new combinations of medicines.
Screening or diagnostic trials
These trials investigate new screening and diagnostic methods to determine whether they can effectively detect diseases.
Prevention trials
Prevention trials test new tools or methods for preventing disease, including medicines, vaccines, vitamins, and lifestyle and diet changes.
Clinical trial phases
Clinical trials often involve multiple phases. The number of participants will be small at first, then increase through later stages of the trial.
Here are the four most common phases.
Phase 1
During Phase 1, a new intervention is tested for the first time with a small group of people (between 20 and 80). The goal is to determine safe dosages and to monitor side effects.
Phase 2
The second phase involves testing with a larger group of participants (usually a few hundred). Researchers want to determine the safety of the intervention and its efficacy, or whether it works as intended.
Phase 3
Phase 3 involves several hundred or even thousands of participants. Researchers compare the intervention to the currently available standard of care, often known as the standard treatment. They may also compare it to other experimental interventions or an inactive placebo, like a sugar pill.
In this phase, they also watch for adverse side effects and collect information to ensure people will use the intervention safely.
Phase 4
This fourth phase occurs after an intervention is approved and already in use by the general population. Researchers will monitor its effectiveness and any side effects from its widespread and long-term use.
They may also investigate whether the intervention can be used for different conditions or alongside other treatments or therapies.
A note on teletrials
A teletrial in clinical research is conducted through a larger hospital but utilises smaller regional hospitals as hubs to extend the trial's reach. This approach aims to include more rural, regional, and remote participants in clinical trials, ensuring broader and more diverse participation.
By leveraging telemedicine technology, teletrials provide these participants with better access to cutting-edge treatments and clinical research opportunities. You can learn more about teletrials by researching the Australian Teletrial Program.
Clinical trial designs
In addition to their type and phase, clinical trials are also categorised by the way they are conducted, or designed.
Clinical trials can have more than one design. Below are the most common.
A controlled trial
A controlled clinical trial is a trial that uses a control group. Trials that do not include a control group are sometimes called uncontrolled trials.
At the beginning of a trial, participants will be allocated to one of two or more groups. One group will be testing the new intervention. The other groups will receive other treatments.
For example, a trial may have these two groups, also known as arms:
- the test group or arm: This group is given the intervention being studied, also known as the experimental intervention
- the control group or arm: This second group is given the standard treatment or a placebo. The test results from this group are not as consequential, as they will reflect what researchers already know.
If a group or groups taking the new intervention show significantly better results than the control group, without any serious side effects, researchers will know the new intervention is working, and the trial may end early.
A randomised trial
If a clinical trial is randomised, or involves randomisation, this means that participants are randomly allocated to testing groups.
In a non-randomised trial, researchers assign participants to the groups or the participants choose which group they’d like to be in.
By randomly allocating participants to groups, researchers can remove their personal bias as a potential contributing factor to the test results. Ultimately, they want to be confident that any different outcomes between groups are due to the new intervention, not other factors.
A blind trial
A blind trial, also known as a masked trial, is also designed to minimise the impact of personal bias on test results. The participants and/or the researchers do not know who is receiving the new intervention and who is receiving a different treatment or a placebo.
In a single-blind trial, the researchers and staff know who is receiving the intervention. In a double-blind trial, neither the researchers nor the participants know who is receiving which intervention or treatment.
This approach ensures that the participants and/or researchers aren’t influencing outcomes with their knowledge of events. For instance, an issue may arise if a participant knows they are receiving a new intervention and is eager to support its development or please the research team. They may report exaggerated benefits or play down the side effects.
It’s common practice for clinical trials to combine one or more of the approaches above. A popular design, particularly for later-stage trials, is the randomised double-blind placebo-controlled study.
It’s important to note that the gold standard of clinical trial design is the randomised controlled trial. A randomised controlled trial (RCT) can be both blind and randomised, meaning participants are randomly assigned to different groups. In a blinded RCT, neither the participants nor the researchers know who is receiving the intervention or the control to prevent bias.
Investigator-led trials: key steps
If you are researching or about to start your own investigator-led trial, it is important to have a roadmap to guide you. Multiple factors will need to be taken into consideration, from your ethical, regulatory and clinical practice to your funding and administrative requirements.
Below are four key steps to consider:
- Trial planning: This pre-trial stage will include a feasibility assessment, devising plans and protocols, finalising a budget, sourcing funding, and recruiting participants.
- Trial initiation: This is your chance to pilot your processes and documentation.
- During the trial: You will manage, monitor, assess and report on the trial, including the experiences of participants.
- End of trial: The trial is concluded, and reports are finalised.
Frequently asked questions
A number of regulations apply to clinical trials in Australia, including national and international ethics guidelines, codes of conduct, and laws. This regulatory framework is designed to ensure research integrity and to protect the interests and well-being of trial participants. All clinical trials in Australia must also be approved by an ethics committee before they can proceed. This is usually granted by one of approximately 200 Human Research Ethics Committees (HRECs) in organisations around the country.
For Australian researchers, a useful resource is the National Standard Operating Procedures for Clinical Trials, including Teletrials, in Australia. This document is designed to help organisations standardise their procedures for clinical trials and teletrials in Australia. It outlines standard operating procedures agreed to by all states and territories.
More information about funding schemes is available from the Australian Research Council (ARC), the National Health and Medical Research Council (NHMRC), and the Department of Health Medical Research Future Fund (MRFF).
