Clinical research is research involving people (participants) that is intended to advance medical knowledge or services. Clinical research can be categorized in several ways. For example:
ClinicalTrials.gov states the two main types of clinical research are observational studies (such as a natural history study) and clinical trials (also known as interventional studies).
The U.S. Food and Drug Administration (FDA) provides a sample list of clinical research categories based on what the researcher is studying, including: treatment research, prevention research, diagnostic research, screening research, quality of life research, genetic studies, and epidemiological studies.
For grant purposes, the NIH categorizes clinical research into four main areas of research: patient-oriented research; in vitro studies that use human tissues that cannot be linked to a living individual; epidemiologic and behavioral studies; outcomes research and health services research.
ClinicalTrials.gov Learn about Clinical Trials
NIH Grants and Funding: Glossary & Acronym List
U.S. Food and Drug Administration (FDA): What Are the Different Types of Clinical Research?
U.S. Food and Drug Administration (FDA): Clinical Research Versus Medical Treatment