Importance of understanding study design
So remember - you need to understand about different types of study designs so that:
- A - you can decide which type of study design is best able to answer your question and
- B - so you know the level and strength of evidence from a particular study design.
We will come back to hierarchy of evidence later on.
One of the problems is that not all research questions can be answered through a RCT either because of ethical issues or for practical issues. Let’s not forget that even when evidence is available from RCTs, it might also be that evidence from other study designs is also relevant.