Organisation of a proposed Cochrane Diet and Nutrition Field.

The Cochrane Collaboration helps people make well-informed decisions about health care by preparing, maintaining and promoting the accessibility of systematic reviews of the effects of healthcare interventions. In all, 51 Cochrane Review Groups are responsible for preparing and maintaining the reviews. Most of these Review Groups are problem-based. However, there are a number of areas or dimensions of health care, such as the setting of care (eg primary care) or the type of patient/consumer (eg older persons), that cannot be usefully conceptualised as 'health problems'. In order to reflect the interests of these dimensions, or 'fields', of health care more effectively, the Cochrane Collaboration created another type of entity: Cochrane Fields or Networks. The core functions of these Fields are described. It is proposed that a new Cochrane Subfield for Diet and Nutrition should be set up to attract a cadre of new reviewers in order to ensure the proper representation of diet and nutrition expertise in the relevant Collaborative Review Groups. The methodological pitfalls of the use of nonrandomised studies will be a key issue for the new Subfield, since the focus of the Cochrane Collaboration's programme of searching databases, journals and conference proceedings has been on the identification of reports of randomised controlled trials (RCTs). Some of these sources will be need to be searched again for non-RCT studies. The financial considerations of establishing of a Cochrane Subfield for Diet and Nutrition are discussed.