Clinical trials are conducted for a number of reasons. While the goal is to enhance medicine and drug discovery while also improving patient safety, there are different types of clinical trials. Understanding what these types are and their roles aids researchers in ensuring thorough, safe, effective and compliant medical research, but can also help you get a better idea of what to expect if you decide to enrol in a clinical trial.

This article will review the different kinds of clinical trials in the medical industry, covering treatment, prevention, observational trials and more.

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What are the different types of clinical trials?

When it comes to exploring different types of clinical trials, it’s important to understand that there are two main categories: observational and interventional clinical trials. Each of these plays an important role in understanding the safety and efficacy of new drugs, interventions and medical techniques. There are also specific types of clinical trials within each of these categories, including pilot studies, feasibility studies, prevention trials, screening trials and treatment trials. The following sections explore these trials, what they involve and how they impact the overall clinical trial process.

Observational trials

An observational trial doesn’t involve an intervention such as a new drug that’s being researched. Instead, it focuses on observing participants in a natural setting without changing anything. Some types of trials that fall into this category include:

  • Cohort studies: A cohort study will observe participants over a period of time and then evaluate a specific outcome. For instance, they can be used to determine the risk that smoking poses in terms of lung cancer by following one group of people who smoke, and another group of people who don’t smoke.
  • Case-control studies: In a case-control study, researchers focus on observing people with a specific condition. This type of study also includes another group that consists of people who do not have this condition.
  • Cross-sectional studies: This type of study will assess data related to a specific point in time. It’s an observational study that’s often used to determine the prevalence of certain diseases or health problems. It can also be used to study specific features of population groups.

Interventional trials

In an interventional trial, researchers will use an intervention to determine how it affects groups of people. There’s still a strong observational element in this type of trial, but instead of focusing on observing people in their natural setting, this trial introduces an intervention. In many cases, the intervention group will be compared to another group that did not receive the drug, intervention, medical device or other element.

Both types of trials interact and provide insight and evidence which can inform the other. By supplying base evidence to work upon, both rely on each other to generate evidence and inform evidence-based medicine.

What are the different types of trials within these two groups?

Now that we’ve considered the two main categories, it’s also important to consider different clinical trials types. Each type has a role to play in enhancing medical knowledge, bringing more effective interventions to the market and improving diagnostic processes and patient treatments. In this section, we’ll explore different types of trials so that you have an idea of what to expect from each.

Pilot studies and feasibility studies

In a feasibility study, the main goal is to determine whether to proceed with something specific. The study will also consider what the most effective way would be going forward. This can include estimating and testing the parameters for sample sizes and identifying any potential barriers or challenges that may arise in later trials.

A pilot study is similar but generally has a more specific design in mind. It acts as a small trial version of the main study to test the main methodologies of the research process to see if they work together to answer the research question, and allows for the adjustment of the trial design if necessary.

For example, a feasibility study could screen patients who are being treated for alcohol addiction to determine the prevalence of liver disease. This type of feasibility study would consider if this type of screening could offer a good approach and provides some initial data to work with.

Another example is a feasibility study that considers whether including MRI brain scans among people with multiple sclerosis can be an acceptable and appropriate protocol when it comes to understanding the efficacy of a treatment plan. The usefulness of these scans was evaluated as part of the check-in process.

Treatment trials

When a treatment trial is conducted, it means there’s a specific intervention or drug that a pharmaceutical company wants to assess. These trials are conducted in four phases, with each introducing more participants to the trial.

In the beginning, the trials evaluate how safe the intervention is and determine the optimal dosage. As the phases progress, the trials also consider how effective the intervention is to treat a specific disease, along with any long-term effects. For example, FluCamp may conduct clinical trials that test specific drugs for their efficacy in treating diseases such as flu. Clinical treatment trials are vital in improving care and advancing medical knowledge for disease treatment, prevention and medical devices.

Prevention trials

A prevention trial will assess the effectiveness of preventative measures that have been developed. This may include the use of vaccines to determine how effective they are at preventing disease when exposed to a specific microorganism. Apart from vaccines, these trials can also evaluate how certain medicines may reduce the risk of disease or assess the preventative impact of lifestyle changes on specific conditions.

A chemoprevention trial, for example, can consider preventative efforts that could be taken to reduce the risk of chemotherapy needed by cancer patients. The trial could also consider prevention techniques that could reduce the risk of specific cancers.

These trials play a really important role as they tell us how certain behaviours, medications, lifestyle factors and other elements affect the risk of disease. They can be helpful when it comes to improving patient care and lowering the incidence of many diseases.

Screening trials

Screening trials focus on screening procedures that are used to detect disease in patients who are asymptomatic. The purpose of these screening procedures is to improve the early detection of disease, which often leads to more successful treatments.

A screening trial can help to provide more details about how cost-effect specific screening methods are. It can then compare the cost-effectiveness to the overall efficiency that the screening technique offers. One example would be to screen women for breast cancer during their annual health checkups and to compare this data to women who did not receive this screening.

Multi-arm multi-stage (MAMS) trials

A multi-arm, multi-stage trial focuses on assessing multiple types of interventions or treatments simultaneously. It helps to reduce the overall time needed to understand more about these interventions and can also be a great way to save on costs. The trial can produce valuable data that can be used to draw up statistical reports to enhance medical knowledge and determine which interventions are more effective for specific conditions.

By making the evaluation of new drugs much faster, it can essentially help to bring better interventions to the market with fewer delays. This means patients with a specific disease can start accessing new treatments that may be more effective than the current interventions.

STAMPED is an excellent example of a MAMS trial. The study started out in 2005 and has since been able to recruit over 10,000 men. The trial focuses on testing various interventions for prostate cancer and has helped make significant progress in improving care for this disease.

Cohort studies

Cohort studies are observational. There are no interventions used. They simply follow specific groups of participants over a period of time. The study usually considers the impact of certain exposures, such as cigarette smoking, alcohol usage, drug abuse, pathogens and other elements. The researchers focus on gaining a better understanding of the outcome following a period of time and the specific exposure. Multiple groups may be included, as this helps to offer a way to compare the data, which can guide healthcare policies and practices.

Case-control studies

Case-control studies are also observational. Cases in these studies focus on people with a defined health condition and compare the data to the controls, which are groups that do not have the disease or condition.

A case-control study can be useful to gain a better understanding of the causes of diseases, how diseases affect people in the long term and even provide more data related to the underlying factors of the condition or issues that contribute to its progression.

Let’s consider an example where a case-control study looks at a group of women with breast cancer. They compare this to the controls, which are women without breast cancer. The researchers can go back and see where there were differences between the groups. Lifestyle factors, dieting habits, exercise routines and medical history are some of the factors that the researchers can evaluate. When they find a common pattern in those women with breast cancer, they’ll compare it to those without and see if this could possibly be a contributing factor to the disease.

What next?

There are different types of clinical trials, and each is important for the medical industry. These studies help researchers understand the prevalence of conditions, consider risk factors for diseases and gain a better idea of how health conditions affect people. They can also be valuable when bringing new interventions to market. FluCamp conducts a variety of clinical trial studies. If you have questions about the safety of clinical trials and how you can make a difference in the medical sector, simply contact FluCamp to find out more.