4.2 Types of Research Studies

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Hello, my name is Ramzi Salloum and today, I will be speaking about types of research studies.

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Today, I will be discussing different types of research studies you may come across in your work as a Citizen Scientist. We will cover some of the main points about each of these study types, and highlight differences between types of studies. I will also be sharing examples of each type of study so that you can better understand what each of these study types means in a real-world setting.

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[Slide shows a side-by-side comparison of experimental and observational studies.]
The two main types of research studies you will come across are experimental studies and observational studies.
In an experimental study, researchers are able to control which participants receive the clinical intervention or treatment- this group of participants is called an intervention group. There is at least one comparison group that receives a different intervention, or no intervention at all which is called a control group, and researchers compare the outcomes of the different groups. This allows the research team to see if the results would be the same no matter what group the participant is in.
Observational studies utilize the data from patients as they are treated by their provider, rather than through randomly assigned groupings from a research team. The comparison groups here are not selected by the research team- instead, the choice of what treatment to choose is up to the patient and their provider. The participants are then followed to observe the results and outcomes.

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A randomized control trial is where participants are randomly assigned to receive a treatment or intervention. This type of experimental study strives to reduce the amount of bias or confounding factors when testing a treatment or intervention. Confounding is when there are multiple things that can impact an outcome, and in most cases, it can be tough to determine what those things are. In a randomized control trial, these confounding factors are taken into account and the requirements for participation are often rigorous to try to eliminate as many confounding factors as possible. This type of design enables researchers to determine if any outcomes are due to the intervention, as opposed to other factors.
Randomized control trials are known as the “gold standard” of clinical trials due to how they are structured and how they leave little room for outcomes to happen by chance. If an outcome takes place in a randomized control trial, it’s almost always because of the intervention or lack of intervention.
One thing that helps researchers understand the full effect of the intervention is called blinding. A single-blind study is when research participants do not know which intervention they receive. A double-blind study is when both the participant and research team are unaware which assignment the participant received. Blinding can help eliminate potential bias in a participant’s actions. For example, persons who receive a drug being tested to treat cancer may stop keeping up with their other prescribed therapies because they feel so strongly that the drug will work. Double-blinding can help control bias in the actions of both the participant and researcher. An example of this may be when a researcher may treat participants differently if they knew the participants received the control therapy which will offer them no benefit.

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Pragmatic Clinical Trials are a type of experimental study that looks at whether the study can be done in a real-world setting, unlike randomized control trials that look for whether something will work in ideal settings. These types of research studies can be very helpful to clinicians, patients, and decision-makers like insurance companies, as these studies can help address practical questions about a study like cost, risks, and benefits. Pragmatic clinical trials are less strict about participant inclusion criteria and allow a wider variety of patients to be involved in real-world settings where health care delivery occurs like community clinics or hospitals. For this reason, pragmatic trials put emphasis on generalizability, or how well something can be done in other settings with other groups of participants. These types of trials also test effectiveness- how beneficial was this intervention or treatment in a real setting?
The polio vaccine studies in the 1950s and studies done in the 1980s and 1990s to find treatment for heart attacks are examples of pragmatic clinical trials.

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Observational studies follow a group of people, called a sample, and use the results from that group to make a conclusion about the population. In observational studies, the variable in question is not controlled, which means that any number of other factors can impact the final results and the research team may not be able to measure what that factor was.
Observational studies can also follow participants over a course of time and collect the data as they are generated, or they can collect data from participants after a treatment or intervention has occurred. The study participants in an observational study are not randomized at all. They are simply followed or observed.
For example, let’s say an observational study is looking into whether young adult smokers develop cancer within 5 years of starting to smoke. The research team may take blood work from participants at the beginning and ask their smoking status. Then, the research team may ask the participants to check in with them periodically throughout the five years to make sure they are still healthy and to see if they are still smoking or not. At the end of the five years, they might do several more tests to see if there is any evidence of cancer in the participants who continue to smoke.

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Comparative effectiveness research is research that evaluates and compares health outcomes, clinical effectiveness, risks, and benefits of two or more already-existing medical treatments, services, or items. These- There are several types of studies that can be considered comparative effectiveness research: reviews of existing research, analysis of existing clinical or administrative data, non-experimental studies that look into data from patient chart information or registries, or experimental studies, including randomized control trials.

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[Acronym used on slide: CER]
Examples of comparative effectiveness research studies can include looking at one medication across different populations to see if there are differences in how the medication works in males vs females, among different ages, or among patients of different ethnicities. For instance, does blood pressure medication work any better in men than women? What about in older people? Is there any difference in how it works in Asians compared to how it works in African Americans?
Another example is to look at what,- one type of treatment against another, such as behavioral therapy like counseling or medication to help someone stop smoking. Did more people stop smoking when they went to group sessions and met with their doctor to discuss techniques to not smoke, or did more people find success by using medication to help their brain stop craving nicotine?
Researchers can also look at the same treatment but in different settings, such as whether a youth physical activity program is more effective at home or at school. Does incorporating the program into existing school time, like during a physical education class, help ensure the program is carried out, or is the school day too busy as is and it is more effective to have students do the program on their own time after they get home from school?

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To summarize what we discussed today:
We went over the different types of research studies that you may come across in your role as a Citizen Scientist. There are additional types of research study designs, but these are the ones you are most likely to come across. We discussed the key attributes of each type of study, and I offered some examples of each.
Knowing more about the different types of research studies will help you be an informed, active reviewer as you look over proposals, research plans, and study information. This knowledge will help you understand why researchers design their research in a certain way, and help ensure that you are prepared to discuss research studies with the researchers who design and run these studies.
Thanks for watching.