Developing valid guidelines: methodological and procedural issues from the North of England Evidence Based Guideline Development Project.

Accepted for publication 12 January 1996 There is increasing interest in clinical guidelines within the United Kingdom. With this interest has come an increasing awareness of the methodological issues involved in guideline development, although reports are limited.' Woolf described three main methods of guideline development: informal consensus, formal consensus, and evidence linked.2 In guidelines developed through informal consensus, the method used most often in the United Kingdom, the guideline panel has poorly defined, often implicit, criteria for decision making. Development by formal consensus, used by many consensus development conferences and Delphi groups, provides "greater structure to the analytical process" but still fails to provide "an explicit linkage between recommendations and quality of evidence."2 Guideline development linked to evidence requires the explicit link between recommendations and the quality of the supporting evidence.' ' This allows the user to make an informed choice about whether or not to comply with recommendations. Guidelines are valid if "when followed they lead to the health gains and costs predicted for them."5 We have previously argued that linking guidelines to evidence is one of three developmental prerequisites necessary to maximise guideline validity,6 the other two being systematic review of the evidence and guideline development occurring within an appropriately multidisciplinary group. These methods are unlikely to be used at a local (as opposed to a regional or national) level as necessary skills are unlikely to be available. Local groups should concentrate on identifying valid regional or national guidelines which they can then adapt to their local needs.7 Unfortunately such valid guidelines are few and descriptions of their development in the United Kingdom are non-existent. This article describes the development of explicit, evidence based guidelines for the primary care management of asthma in adults and for stable angina,8-12 two chronic conditions, predominantly managed in primary care and important because of their associated morbidity and mortality. 13 We present our experiences and the methodological issues considered during guideline development, both for those who are involved in this process and for those who wish to know more about the practicalities. Setting up the guideline development project To develop guidelines successfully it was necessary to convene four groups: a project team; a project management group; and two guideline development groups. The project team was composed of the principle investigator, a junior research associate employed to work full time on the project, a cardiologist, and a chest physician. The role of the project team was to undertake the day to day running of the project; this involved the identification and interpretation of relevant evidence, the convening and running of the guideline development groups, and the production of the resulting guidelines. The project management group was composed of specialists in guideline methodology and a health information expert; their role was to provide technical advice on a formal or informal basis throughout the project. The guideline development groups were to produce guideline recommendations in the light of the evidence.