The investigator does not control the parameters of the exposure.
These designs are observational studies.
They are designed to discover an association between exposure and an illness.
| Advantages | Disadvantages |
|---|---|
| The investigator does not intervene | The main drawback of observational studies (whether they are descriptive or analytic) are systematic errors and biases (confounding bias or ranking bias) |
| Exposure occurs "naturally" |
The interpretation of the results from these studies must take into account the context and the limitations of the studies.