The guidance has been written for those with an understanding of health research but who are new to systematic reviews; those with some experience but who want to learn more; and for commissioners. We hope that experienced systematic reviewers will also find this guidance of value; for example when planning a review in an area that is unfamiliar or with an expanded scope. This guidance might also be useful to those who need to evaluate the quality of systematic reviews, including, for example, anyone with responsibility for implementing systematic review findings.

Given the purpose of the guidance, the audience it is designed for, and the aim to remain concise, it has been necessary to strike a balance between the wide scope covered and the level of detail and discussion included. In addition to providing references to support statements and discussions, recommended reading of more specialist works such as the Cochrane Handbook,14 Systematic Reviews in the Social Sciences,4 and Systematic Reviews in Health Care15 have been given throughout the text.