Retrospective analyses

In a retrospective study analysis, existing questionnaires, medical records, and data generated by other methods are analyzed.

There are two types of retrospective cohort studies:

• retrospective case-control studies
• retrospective case series

Retrospective studies are often faster and easier to conduct than prospective cohort studies and can be extremely valuable:

• the use of retrospective study design increases the chance of gaining new medical knowledge about a rare disease (case-control studies).
• can be used to generate a study hypothesis to be investigated by randomized, controlled, prospective studies.
  

Another advantage of retrospective analyses is that data from daily practice are observed.

Precise knowledge of current guidelines on methodology, procedure and search criteria for dedicated questions are the basis for meaningful and valid results.