Efficient searching for NICE public health guidelines: Would using fewer sources still find the evidence?

Systematic searches are integral to identifying the evidence that is used in National Institute for Health and Care Excellence (NICE) public health guidelines (PHGs). This study analyses the sources, including bibliographic databases and other techniques, required for PHGs. The aims were to analyse the sources used to identify the publications included in NICE PHGs; and to assess whether fewer sources could have been searched to retrieve these publications. Data showing how the included publications had been identified was collated using search summary tables. Three scenarios were created to test various combinations of sources to determine whether fewer sources could have been used. The sample included 29 evidence reviews, compiled using 13 searches, to support 10 PHG topics. Across the PHGs, 23 databases and six other techniques retrieved included publications. A mean reduction in total results of 6.5% could have been made if the minimum set of sources plus Cochrane Library, Embase, and MEDLINE were searched. On average, Cochrane Library, Embase, and MEDLINE contributed 76.8% of the included publications, with other databases adding 11% and other techniques 12.2%. None of the searches had a minimum set that was comprised entirely of databases. There was not a core set of sources for PHGs. A range of databases and techniques, covering a multi-disciplinary evidence base, was required to identify all included publications. It would be possible to reduce the number of sources searched and make some gains in productivity. It is important to create a tailored set of sources to do an efficient search.