Medical research is essential for advancing the understanding of health, diseases, and treatments. There are many types of studies that serve different purposes.

Medical research, or health research, generally describes any form of research that ultimately aims to improve human health. It involves a wide range of scientific fields with the shared goal of improving the understanding and treatment of health conditions.

To do this, researchers use a variety of medical research studies that serve different purposes, use different research methods, and provide different levels of evidence.

Doctors and nurses at work in medical research clinic-2.Share on Pinterest
The Good Brigade/Getty Images

Generally, researchers categorize research into one of three categories:

  • Basic research: Also known as “pure” or “fundamental” research, this type of scientific research typically describes studies done with the aim of improving scientific theories to help improve knowledge and deepen understanding.
  • Clinical research: This refers to research in people, or tissue from people, to help understand health and diseases. These studies aim to find new and better ways to detect, diagnose, treat, and prevent diseases.
  • Translational research: Also known as “bench to bedside,” this type of research describes the process of applying, or translating, scientific knowledge from the laboratory to develop real-world health solutions, such as new tests, treatments, and prevention strategies.

This type of study describes when researchers observe outcomes and make no attempt to affect the outcome. Typically, observational studies may help reveal possible associations, but cannot prove cause and effect. Examples include:

  • Cohort studies: These studies involve people who share common characteristics. The researchers observe how certain exposures or risk factors can influence their health or the development of diseases. For example, one group may drink alcohol, while the other does not. The study would then observe how participants’ health develops over a set period and whether people become ill.
  • Case-control studies: Also known as retrospective studies, these compare two groups of people. One group may have a specific condition (the case), while the other group will not (the control). As such, this study investigates whether certain factors may have links with the health condition.
  • Cross-sectional studies: This type of study analyzes data from a group of people at a specific point in time. This can provide a snapshot that may help highlight the prevalence of disease with certain health behaviors.

Unlike observational studies, interventional studies involve the researchers actively administering an intervention, such as a treatment, to some of the study participants. By doing this, they can evaluate the effect of the intervention on the outcome. Some examples include:

  • Randomized controlled trials (RCTs): This type of study randomly assigns participants to different groups. In the experimental group, participants receive the intervention. In the control group, people will receive a standard treatment or a placebo. By comparing the groups, researchers can determine whether the experimental intervention has a true effect on the outcome. This can help to reduce potential bias.
  • Blinded and double-blinded trials: Blinded studies are trials where those involved do not know which group they are in. For single-blind studies, the participants do not know which group they are in. For double-blind studies, neither the participants nor the researchers know the group assignments. These studies can also help prevent bias.
  • Non-randomized trials: These studies are similar to RCTs, but lack random assignment. Participants may choose their group, or the researchers may assign them. These studies may be more practical in some real-world settings, but they are generally more prone to bias.

These are not original studies, but they are a common form of research. They are a type of analysis that synthesizes results from multiple studies. The aim of a systematic review is to answer a specific research question by summarizing current evidence.

When performing a systematic review, many researchers also perform a meta-analysis. This is a type of research that uses statistical techniques to combine the results of studies addressing the same research question to produce a more reliable overall conclusion.

When interpreting research results, it is important to understand the type of study and the conclusions researchers can draw from it.

For example, an observational study may suggest that people who drink coffee have lower rates of heart disease. However, as an observational study, it cannot prove any cause and effect. But this theory can help shape an interventional study. Researchers could perform a randomized trial that could help determine whether drinking coffee directly causes that benefit.

Study design and methodology can also affect the reliability of findings. For example, a larger, randomized, double-blinded trial will provide more trustworthy evidence than a smaller, non-randomized study.

Medical research describes studies that aim to improve knowledge of health. Different types of studies serve different purposes and have different strengths and weaknesses. For example, observational studies can highlight potential links, while interventional studies can show whether treatments have an effect.