Studies whose purpose is to evaluate the safety, effectiveness, or utility of an exposure include studies of different types of treatments.

For example, drugs, nutrition, exercise, surgery, or treatment with modern medical equipment (e.g., CT scans, prenatal diagnosis with amniocentesis, chorionic villus sampling, fetal endoscopy) and disease prevention (vaccines, diets, toothpaste fluoridation). Research on normal human functioning and development includes studies of the human body during exercise, fasting, eating, sleeping, learning, under stress or sensory stimulation.

Some studies compare the functioning of a particular physiological system at different stages of body development, such as infancy, childhood, adolescence, adulthood, and old age. Others aim to determine normal childhood development so that abnormalities can be identified. Sometimes studies, especially case histories, are conducted to make and refine hypotheses. Disease-specific research is required before new, improved treatments, prevention, and diagnosis can be developed (e.g., the study of biochemical changes associated with HIV infection, schizophrenia; or neurological changes associated with senile dementia, Alzheimer’s disease). Research in the field of the human genome and genetic markers is aimed at creating new approaches to understanding the pathogenesis and etiology of pathological processes and ways to control the development of diseases.

In some biomedical studies, subjects perform routine tasks (e.g., exercising, repeating a series of words, or responding to various sensory stimuli). In doing so, their physiological performance is measured. Although many of the procedures used in biomedical research resemble those used in routine examinations, there is sometimes a need for more precise invasive procedures such as biopsy, endoscopy, and fluoroscopy. Studies designed to obtain information about normal physiology or disease are not usually associated with the evaluation of a medical intervention, it may require additional procedures.

This category includes studies performed on experimental animals, and biological materials (tissue, blood, urine, etc.). In the latter case, the researcher records the samples in such a way that the subjects cannot be identified with the associated identifying features.

It also includes studies based on the study of archival materials (more often medical histories), where information about each individual is recorded in such a way that his or her identity cannot also be established.