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Research Guides

FCS 205: Concepts in Human Nutrition : Types of Medical Research Studies

About Medical Research

The type of selected medical research study varies depending upon the population/entity being researched and information being gathered. The study design that is chosen is a very important piece of the process, as it often influences the quality and value of the conducted research. On this page, you will find the most common types of medical research explained.

To learn more please visit, Types of Study in Medical Research.

Primary Research

Basic Research (Experimental Research):

In basic medical research, all experiments include at least one independent variable. Effects on the dependent variable are then studied. Hypothesis and statements are made to guide research. The procedure and experimental design of these studies are precisely crafted. External validity is often an issue due to the transferability of lab findings and findings from non-human subjects to everyday life. Study types include:

  • Animal experiments
  • Cell studies
  • Biochemical, genetic, and physiologic studies
  • Drug and materials studies
  • Development and improvement of analytical procedures

Clinical Research:

Clinical research can be both invterventional (experimental) and non-interventional (observational). Studies often focus on drug trials, medical devices or surgical, physical, or psychotherapeutic interventions. These studies regularly use human subjects and therefore must pass extensive legal and ethical requirements. The gold standard for such studies is: informed consent, randomization, and double blinding. 

  • Interventional (Experimental) research - compare treatment procedures with a patient population
  • Noninterventional (Observational) research - are patient related, providing individual treatment

Epidemiological Research:

Epidemiological studies focus on investigating the causes and treatments of disease(s) over time. Such studies may be used when clinical intervention studies cannot.

  • Interventional (Experimental) research - comprised of field studies and group studies
  • Noninterventional (Observational) research - cohort, prospective, historical, case control, cross-sectional, and ecological studies

Secondary Research


Meta-analysis is the statistical analysis of results. In this research, results from primary research are studied with the purpose of assimilating the findings (thus producing secondary research). Meta-analysis is primarily used in medical research to evaluate the efficacy of treatment. However, given varied types of study employed, creating a consensus through meta-analysis can be intricate.  


A review is a systematic investigation into a topic, with the aim to highlight key issues or important points. A review is considered secondary research as it reinterprets the findings of primary research. 

Image and text were composed in conjunction with viewing Types of Medical Research, by Bernd Rohirg, Jen-Baptist Prel, Daniel Wachtlin, and Maria Blettner.