Types of clinical trials in dementia research

• Small-scale studies that test whether a larger trial would be practical and safe.
• These studies help researchers to refine their methods and identify potential issues early on.
• 'Pilot studies' may also known as ‘feasibility studies’.

• These trials aim to develop ways to stop a disease before it starts.
• Often, they will involve healthy participants or those at a higher risk of developing disease, such as people with family history of dementia.
• Prevention trials test new interventions, such as medication, vaccines or lifestyle changes, in people who have not yet developed any symptoms.

• Screening trials investigate new ways to detect diseases early, before symptoms appear.
• They may involve a range of methods, such as scans, blood tests or genetic testing.

• RCTs are often described as the ‘gold standard’ for evaluating the effectiveness and safety of new therapies or devices.
• They test the safety and effectiveness of new interventions under controlled conditions.
• Participants are randomly assigned to either a treatment or control (placebo) group.
• Helps researchers to make sure that results are unbiased and reliable.

• Multi-arm multi-stage trials can be designed as randomised controlled trials (RCTs), or patients may be assigned to groups based on shared characteristics, such as genetics.
• Designed to test either:
  • A single drug in people with different types of dementia within the same study, to see whether the new therapy may benefit all participates/to understand who benefits the most.
  • Multiple groups receiving different drugs in parallel, allowing arms of the study with ineffective therapies to be stopped early and new arms with promising drugs to be added.
• Their aim is to efficiently test the safety and effectiveness of new interventions for a disease, such as new drugs, and to speed up getting new breakthroughs into the clinic.
• Allows researchers to adapt the trial as it progresses, dropping ineffective treatments and focusing on promising ones.

• These trials are always randomised.
• They are used to test new interventions for a disease.
• Neither participants nor researchers know who is receiving the study treatment or a control treatment (placebo). This reduces bias and ensures reliable results.
• Information about which participants are receiving which treatment is only revealed after the trial ends, unless there’s a medical emergency.

• These studies help researchers to monitor the long-term safety of treatments, or to compare different treatments to one another.
• Both participants and researchers know which treatment is being given to participants.
• Some trials start as double-blind and later switch to open-label extensions, which are frequently used to gain information about certain treatments over time, including how tolerated the treatment is amongst participants.

Placebo-controlled trials help researchers compare the real treatment against no treatment. This helps to determine the effectiveness and safety of new therapies or devices, and help researchers measure the ‘placebo effect’, where people feel better simply because they believe they’re being treated.  

By controlling for this effect, researchers make sure that any benefits participants feel are due to the treatment itself.

Randomisation helps researchers make sure that participants are assigned to treatment or control groups by chance. This ensures that groups are equally balanced (equal number of people receive placebo or real treatment). It also reduces bias and makes results more reliable.

Many randomised trials are also double-blind, which means that neither you nor the research team knows which group you are in. You’ll always be treated as if you are receiving the active treatment, and safety will be closely monitored.  

In emergency situations, the group you are in might be revealed when it is important for your care.