A guide to systematic reviews

Systematic reviews have become widely used for evaluating evidence across all fields of biomedicine. The objective of a systematic review is to provide a comprehensive and contemporary appraisal of research using transparent methods whilst aiming to minimize bias. In essence, research methodology is employed in the conduct of the review. Such reviews are therefore fundamentally different from traditional 'narrative' review articles in their purpose and in their potential to aid clinical decision-making. This paper is a guide to the rationale and nature of systematic reviews and will provide a background to understanding their use in clinical practice.