Types of Studies - L1

Scientists evaluate all relevant evidence when deciding about potential health hazards, including epidemiology, animal, and cellular studies.

A mix of studies in different research areas is essential for the evaluation of potential adverse health effects of human exposure to an agent. Different types of studies investigate distinct aspects of the problem.

Laboratory studies on cells aim to elucidate the fundamental underlying mechanisms that link exposures to biological effects. They try to identify mechanisms based on molecular or cellular changes that are brought about. The key limitation in these studies is that single cells or tissues are removed from their normal living environment which may affect their response to the exposure.

Another type of study, involving animals, is more closely related to real life situations. These studies provide evidence that is more directly relevant to establishing safe exposure levels in humans and often employ several different field levels to investigate dose-response relationships.

Epidemiological studies or human health studies are another direct source of information on long-term effects of exposure. These studies investigate the cause and distribution of diseases in real life situations, in communities and occupational groups. Researchers try to establish if there is a statistical association between exposure and the incidence of a specific disease or adverse health effect. However, epidemiological studies are costly and they involve measurements on very complex human populations and are difficult to control.

More information...

Types of Studies:EPIDEMIOLOGY - L2

What is epidemiology?
What can epidemiology tell us?
How are epidemiology studies conducted?
What are the different types of epidemiology study designs?
What are the limitations of epidemiology studyies?
How are the results of epidemiology studies interpreted?

What is epidemiology?




What can epidemiological studies tell us?



How are epidemiological studies conducted?



What are the different types of epidemiological study designs?

Some common types are:

Prospective Cohort


Case Control





What are the Limitations of Epidemiological Studies?






How are the results of epidemiological studies interpreted?


The five main criteria for establishing a likely association are:

1. the strength of association - the relationship must be clear
2. consistency - repeatable in other study populations
3. temporality - exposure must come before the disease
4. plausibility - it must make sense biologically



Additional resources...

Epidemiology Explained - L3

Additional Information on Epidemiology

Health Authority & Educational Resources


Other Resources