About clinical trials

Read more about clinical research, including the different phases of clinical trials and the importance of including older participants in clinical trials.

What is clinical research?

Clinical research helps us answer specific questions about a drug or treatment, such as:

  • Is it effective?
  • Is it more effective than an established treatment?
  • Is it safe and what are its side effects?

The development of a new drug can take more than 10 years. Although long, this length of time is vital to ensure each drug is tested rigorously.

During this time, an investigational drug (one that is being studied as a new treatment) passes through three stages of research that are called Phases each with specific objectives. If a drug passes through all three phases successfully, it’s submitted to regulatory authorities for approval for use in the general public. After an investigational drug has been approved, additional studies may be conducted in Phase 4 research.

Clinical trial phases

With each phase of clinical trials, our knowledge about a medicine and its safety and effectiveness grows.

  • In Phase 1 trials, researchers test a new drug or treatment in a small group of people (20-80) for the first time to evaluate its safety, determine a safe dosage range, and identify side effects. Phase 1 participants are often healthy volunteers that do not have any disease.
  • In Phase 2 trials, the study drug or treatment is given to a larger group of people (100-300) with the condition to be treated to see if it is effective and to further evaluate its safety.
  • In Phase 3 trials, the study drug or treatment is given to large groups of people (1,000-3,000) with the condition to be treated to confirm its effectiveness, monitor side effects, compare it to commonly used treatments, and collect information that will allow the drug or treatment to be used safely.
  • In Phase 4 trials, studies look at real-world experience in the general population over a long time and provide additional information on the drug’s risks, benefits, and optimal use. This may include looking at additional conditions or populations.

Why does research matter?

Clinical research can change lives. Clinical trials are the most valuable, pragmatic and useful source of information for scientists to understand whether a treatment or a lifestyle change is effective. Clinical research can give us clear insights and answers about the safety and effectiveness of drugs and therapies. Clinical research is the vehicle through which researchers can find new medicines, improved versions of available medicines, and new uses for available medicines.

Every medicine that you take has been studied by clinical research. Clinical trials are made possible because of people like you. Volunteer participation of both healthy and those diagnosed with dementia (or other illness) is the only pathway to advances in treatment. Clinical research and clinical trials open new doors to finding new and more effective ways to prevent, diagnose and treat dementia. It is almost impossible for clinical research to find crucial answers without volunteers’ participation.

Why are older and diverse participants needed for clinical trials?

Participants from different ages (as well sexes, races and ethnicities) are needed for clinical research. Diversity in clinical research is crucial. When trials include participant populations that are not diverse, the outcomes of the trial may not apply to the general population (they may not “generalise”) and the findings are less valuable. Diversity of participants means that the research results may be “stronger” and may apply more widely.

The participation of older people in clinical trials is crucial as scientists can arrive at more accurate conclusions and can learn more about how new drugs, therapies, medical devices, surgical procedures, or tests will work for older people. The majority of older people have more specialised health needs than younger people. As people grow up and age, their bodies may have different reactions to drugs. So, older people may need different dosages or amounts of drugs in order to have the expected result. Moreover, side effects may have a different impact or severity in older people. Consequently, older people’s participation in clinical trials is vital because it produces more accurate results, which can lead to more effective treatments. 

Participants from different ages (as well sexes, races and ethnicities) are needed for clinical research.

However, researchers know that it may not be easy for some older people to join a clinical trial. For instance:

  • Is it possible for a person to participate in a clinical trial that is looking only at one health condition while she/he has many health problems?  
  • Is it possible to participate in a clinical trial if you are frail or have a disability?

In order to have a clear answer to the above questions as well as to other questions that you may have, it is always important to for potential participants to discuss these issues and any concerns with the trial coordinator.

Content adapted with kind permission from Eli Lilly and Company, National Institutes of Health (NIH) and Center for Information and Study on Clinical Research Participation.

Learn more about clinical trials

10 things to know about clinical research

Understanding trial participation

If you’re considering participating in a clinical trial, there’s a lot to think about. The topics covered on this page can help you get the information you need to guide your decision. Read More