In modern medicine, clinical trials are the gold standard of clinical research. Clinical trials are well-controlled, function under a strict regulatory environment, and are a type of research study that is performed on people to evaluate a medical, surgical, or behavioral intervention. This intervention could include drugs, cells, other biological products, surgical procedures, radiological procedures, medical devices, behavioral treatments, and preventive care. People of all ages can take part in clinical trials, and they are a primary way for researchers to find out if new treatments, drugs, or medical devices are safe and effective. They also can be used to test ways to find diseases earlier while others find ways to prevent health problems altogether.
There are four phases of clinical trials:
This phase typically tests a new drug or treatment on a small group of people (20-80) to evaluate safe dosage ranges and identify side effects
This phase introduces a larger group of people (100-300) to test for effectiveness and monitor for any adverse effects. This stage can last several years.
This phase is used to gather more information about safety and effectiveness by studying larger populations (up to 3,000 people) in different regions using different dosages. This is the step before approval with positive test results. This stage can also last several years.
This phase is after FDA approval when a device or drug’s effectiveness and safety are monitored in wide, diverse populations over a longer time frame.
Typically, a clinical trial will look something like the following:
- Research staff explain the trial and gather personal information.
- You sign a consent form.
- You are screened to make sure you qualify.
- If you accepted, you schedule a first visit or baseline visit where research conducts cognitive or physical tests.
- You are randomly assigned to a treatment or control group.
- You follow the trial procedures and report any issues or concerns to researchers.
- Some trials require you to visit the research site at regularly scheduled times for new cognitive or physical evaluations or discussions with staff. This is also when the research team will collect information about the effect of the intervention, your safety, and your well-being.
- You continue to see your regular physician for the usual healthcare.
The Beginning of Clinical Trials
The definition of a clinical trial according to the International Committee of Medical Journal Editors is “any research project that prospectively assigns human subjects to intervention and comparison groups to study the cause-and-effect relationship between a medical intervention and a health outcome.” With this definition in mind, some versions of controlled clinical trials have existed for thousands of years with the first recorded manifestations as a variety of attempts to compare interventions before later incorporating randomization, blinding, and placebos.
The First Documented Trial
The first documented evidence of an actual clinical trial that fit this definition occurred in 500 BC and was outlined in the book of Daniel from the Old Testament. This trial was a nutritional experiment where Daniel and his three brothers were assigned to a diet of only vegetables and water and were compared with men who followed the king’s diet of meat and wine. Daniel and his brothers were documented as the healthier group based on their diet. The accuracy of the trial and account has not been confirmed but this has been the basis of a clinical trial that was clearly demonstrated and documented.
The First Formal Trial
The first formal clinical trial was documented in 1025 AD by Persian physician and philosopher Avicenna who established groundbreaking rules for testing drugs and remedies. While these rules may have changed and adapted, this is still considered one of the first real descriptions of formal clinical trials.
In 1747, Naval surgeon James Lind famously conducted the first controlled clinical trial. This trial was conducted to find a remedy for a group of sailors who were suffering from scurvy. In this trial, he divided the 12 sick sailors into six pairs and gave them each a different dietary supplement: cider, vinegar, seawater, sulfuric acid, oranges, and lemons. His documented results revealed that the sailors who received oranges and lemons were able to recover, proving that citrus is a critical part of a sailor’s diet.