Systematic Reviews & Evidence Synthesis

Your overall search design and process is your initial data collection instrument for your evidence synthesis project.

In general, all evidence synthesis search designs follow these basic precepts:

• Systematic search design is based on structured “concept” searching
• Comprehensive searching is as sensitive as possible but as precise as necessary. In order to achieve this, systematic and comprehensive search design:
  • Always uses both keywords AND controlled vocabulary (if available in the database)
  • Uses the database syntax (field tags, Boolean operators, keyword modifiers, proximity operators) to increase sensitivity while balancing precision
  • Relies on database searching for structure and additional methods for further comprehensiveness
• Systematic searches should always be peer reviewed
• The search design and process should be transparently reported so that other researchers (or you) could run the searches again and get the same results

Search designs in evidence synthesis projects use processes that are both more systematic and much more sensitive than regular database searches so as to reduce the potential for bias in the retrieval of results for screening and analysis. Methods guidelines will provide you with a high level overview of these search processes and should be reviewed.

Search Design Guidance from Methods Guidelines

The Search Phases (Timeline)

There are six phases to the search process:

1. Exploratory Searching = collect seed articles, similar review articles, potential search terms, and refine your ideas
2. Protocol and Primary Search Design = plan and report in your protocol your entire search process including both databases and additional search/retrieval methods along with a comprehensive and systematic search design for one primary database
3. Database Search Translation = translate the search design for your primary database so it will function accurately and equivalently in all other database you will search
4. Peer Review Search Designs = have your search designs reviewed formally or informally for accuracy
5. Conduct Database Searches = run your searches and export all results from databases
6. Conduct Additional Search/Retrieval Processes = conduct additional search/retrieval processes as outlined in the protocol phase

The Search Skills (Process)

While the phases map out what occurs temporally, there are twelve specific arenas of skills, tools and information you need to know to accomplish those phases. This guide is organized by these twelve components and links in the list below [coming soon] take you to the relevant section.

1. Plan you search documentation process
2. Identify the searchable core concepts for your research question
3. Select databases and/or registries to search
4. Harvest and list all search terms (keywords, phrases, and controlled vocabulary) for each searchable concept
5. Modify and structure the keywords and phrases appropriately (start with one primary database, then translate for all other databases as necessary)
6. Identify how to tag the appropriate database fields for all keywords and controlled vocabulary (start with one primary database, then translate for all other databases as necessary)
7. Connect all modified and tagged keywords and controlled vocabulary properly using Boolean operators, parenthesis, and/or line searching (start with one primary database, then translate for all other databases as necessary)
8. Test and refine the search design
9. Get the search design peer reviewed
10. Conduct all database searches and export all search results
11. Conduct additional search/retrieval processes outside of database searches
12. Remove duplicate results from all combined search results