Introduction

Over the last decade clinical practice guidelines have become an increasingly familiar part of clinical care. Defined as “systematically developed statements to assist both practitioner and patient decisions in specific circumstances”,¹ they are viewed as useful tools for making care more consistent and efficient and for closing the gap between what clinicians do and what scientific evidence supports.² The broad interest in clinical guidelines is international³⁴ and has its origin in issues that most healthcare systems face: rising healthcare costs; variations in service delivery with the presumption that at least some of this variation stems from inappropriate care; and the intrinsic desire of healthcare professionals to offer, and patients to receive, the best care possible. Within the UK there is ongoing interest in the development of guidelines⁵ and a fast developing clinical effectiveness agenda within which guidelines figure prominently.⁶⁷

During the same 10 year period the methods of developing guidelines have steadily improved, moving from solely consensus methods to methods that take explicit account of relevant evidence. This improvement should make guidelines more valid; guidelines are valid if “when followed, they lead to the improvements in health status and costs predicted by them”.¹ In order to maximise validity, three areas of the guideline development process are important^8–10:

1. identification and synthesis of the evidence should be done using the methods of systematic review¹¹ to maximise the appropriate identification of evidence;

2. the guideline development group should be appropriately multidisciplinary to ensure full discussion of relevant evidence, associated service delivery issues, and the appropriate construction of recommendations;

3. the recommendations in the guideline should be clearly and explicitly linked to the evidence supporting them.

To date, however, most guidelines have taken a relatively narrow view of evidence, focusing predominantly on effectiveness …