Studies can be categorised in different ways, and different names are sometimes used for the same study design.
Examples of study designs that can be used to assess treatment effects include randomized studies and non-randomized studies.
Those two broad categories of studies can be further divided into different types of randomized and non-randomized studies. For example, types of non-randomized studies used to assess treatment effects include cohort studies, case-control studies, and controlled before-after studies, among others.
Some study designs are more suited than others for answering specific types of research questions.
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