Hi Jon,
A Systematic Reviews is a huge effort to compile, assess and synthesise the evidence available to facilitate a well informed decision about a specific question. So you could extract several reasons from this definition:
1.To facilitate a well informed decision.
2.To assess the quality and synthesise the accumulated evidence.
3. To put together published and unpublished evidence.
4. to avoid harm (Cochrane´s logo is a good example).
5. to promote beneficial changes in the clinical practice (If the SR has a strong and quality evidence)
6. To develop a meta analysis. (Maybe you have several small trials and you could combine their results)
7. To collect the adverse effects of an intervention.
8. To compare the effect of several interventions ( A broad systematic review).
9. To develop clinical practice guidelines and clinical pathways.
10. To avoid unfair heterogeneity of the clinical practice.
Sure there are more reasons that I am not able to see but above all I see the SRs as a high quality proof that can produce a knowledge and clinical practice revolution in order to avoid unnecessary harm.
Best wishes,
Rocío Rodríguez
Information Specialist
