A Method for Maximising Comprehensiveness in Systematic Searches, and the Utility of this Approach for the Cochrane Health Promotion and Public Health Field

Article type
Authors
Kavanagh J, Brunton G, Harden A, Rees R, Oliver S, Oakley A
Abstract
Objectives: To measure the impact on comprehensiveness of searching specialised registers when searching systematically for evidence to support reviews of health promotion interventions. To describe the impact of this strategy upon the specialised register BiblioMap.

Background:The EPPI-Centre is joint convenor of the Cochrane Health Promotion and Public Health Field. It compiles and maintains BiblioMap, a database of bibliographic references of health promotion-related literature. All BiblioMap records have been retrieved from a systematic search and coding strategy ("mapping"), developed by the EPPI-Centre, and conducted as a preliminary stage of all systematic reviews in the EPPI-Centre. This paper will first analyse elements of the search strategies for two systematic reviews in progress, and then describe the contribution BiblioMap has made to the Cochrane Health Promotion and Public Health Field.

Methods:No one electronic database comprehensively catalogues research relevant to the multi-disciplinary field of health promotion. Two ongoing systematic reviews of the barriers and facilitators to healthy eating and physical activity in children required systematic searches to identify diverse types of evidence; outcome evaluations of health promotion interventions; observational studies; and systematic reviews. To maximise comprehensiveness we conducted searches of major databases (MEDLINE, Embase, CINAHL, ERIC, SSCI and PsychLit) in a number of disciplines (biomedicine, social science and education) and specialised registers (BiblioMap, DARE, HealthPromis, the Cochrane Controlled Trials Register, the Cochrane Heart Group register, and HEBS). A strategy combining three conceptual components (children; barriers and facilitators of health promotion; and healthy eating or physical activity) was devised in MEDLINE and translated to other databases. Methodological filters for study design were not used as these reduce the sensitivity of searches.

These search methods have been developed at the EPPI-Centre since 1996.All topic relevant references located by this method have been entered onto BiblioMap and coded using a standardised keywording strategy including research design.Coding allows the retrieval of references to RCTs and CCTs, for eventual submission to the Cochrane Controlled Trials Register (CCTR).

Results:This strategy for the two reviews in progress retrieved 19,023 abstracts and citations, reduced to 1,524 after preliminary screening for relevance. 17% of studies included at preliminary screening were retrieved from specialised registers alone.

Bibliographic Source No of Hits No of relevant hits % relevant hits
"Major" databases 17,153 1,267(unique 1,147) 7%
"Specialised" Registers 1,870 377(unique 257) 20%

BiblioMap currently contains 9,577 references of which 873 (8.9%) were only found on specialised registers. Since January 2001 the EPPI-Centre has submitted 1072 records to the CCTR, and work is in progress for the next submission in March 2002. BiblioMap will be updated with references found from the current reviews

Conclusions: Omitting methodological filters for study design retrieves all study types without compromising sensitivity. Utilising specialised registers maximises comprehensiveness, with less complex searches required due to the specificity of the contents. This method may improve the comprehensiveness of searches for systematic reviews of other multi-disciplinary health topics and may be of particular use to other Cochrane Fields in supporting reviewers within their field.