The NICE OECD countries’ geographic search filters: Part 1—methodology for developing the draft MEDLINE and Embase (Ovid) filters

Abstract

Objective: There are no existing validated search filters for the group of 37 Organisation for Economic Co-operation and Development (OECD) countries. This study describes how information specialists from the United Kingdom’s National Institute for Health and Care Excellence (NICE) developed and evaluated novel OECD countries’ geographic search filters for MEDLINE and Embase (Ovid) to improve literature search effectiveness for evidence about OECD countries.Methods: We created the draft filters using an alternative approach to standard filter construction. They are composed entirely of geographic subject headings and are designed to retain OECD country evidence by excluding non-OECD country evidence using the NOT Boolean operator. To evaluate the draft filters’ effectiveness, we used MEDLINE and Embase literature searches for three NICE guidelines that retrieved >5,000 search results. A 10% sample of the excluded references was screened to check that OECD country evidence was not inadvertently excluded.Results: The draft MEDLINE filter reduced results for each NICE guideline by 9.5% to 12.9%. In Embase, search results were reduced by 10.7% to 14%. Of the sample references, 7 of 910 (0.8%) were excluded inadvertently. These references were from a guideline about looked-after minors that concerns both OECD and non-OECD countries.Conclusion: The draft filters look promising—they reduced search result volumes while retaining most OECD country evidence from MEDLINE and Embase. However, we advise caution when using them in topics about both non-OECD and OECD countries. We have created final versions of the search filters and will validate them in a future study.

The NICE OECD countries’ geographic search filters: Part 2—validation of the MEDLINE and Embase (Ovid) filters

“…There are currently thirty-eight OECD country members [ 6 ]. We previously drafted the NICE OECD countries' geographic search filters for MEDLINE and Embase (Ovid) [ 7 ] using our experience gained during the creation of the NICE UK geographic search filters [ 8 , 9 ]. There is a nonvalidated filter search strategy available for OECD countries, but no validated filters previously existed [ 5 ].…”

“…The purpose of creating the draft OECD filters was to assess their feasibility for finding evidence about OECD countries. The draft version of the filters used in the development study were promising, as they retained most OECD country evidence while reducing search result volumes [ 7 ].…”

“…Following the development study, we updated and finalized the draft filters for the validation process [ 7 ]. The purpose of the current study was to validate the final version of the filters and evaluate their effectiveness and efficiency.…”

“…The NICE OECD countries' search filters take the unusual approach of finding evidence about OECD countries by excluding evidence about non-OECD countries. Detailed information about the structure and content of the filters is available in our previous paper [ 7 ]. Briefly, the filters are based on the commonly used “humans” search limit which was first appended to a search filter for systematic reviews [ 7 , 10 ].…”

“…Detailed information about the structure and content of the filters is available in our previous paper [ 7 ]. Briefly, the filters are based on the commonly used “humans” search limit which was first appended to a search filter for systematic reviews [ 7 , 10 ]. The humans limit excludes database records that only have subject headings for animals and retains all other database records to find database records about humans [ 7 , 10 ].…”