An effective research question tells the reader about the systematic review by defining the parameters and purpose of the research. It also guides the development of a terms list which can be utilized for effective searching in the various databases. Depending on the type of research question, there are several formats available to help you construct your query. We will focus on PICO in this guide for developing clinical questions. The articles below address other formats.
The research question is the starting point for effective search term selection. Once the question and inclusion/exclusion criteria have been agreed upon by the systematic review team, a "terms list" is developed. The team expands this search terms list by brainstorming for alternative terminology, synonyms or related concepts in either keyword or subject heading format (see 'Indexing' below). This "master" search terms list may need modification due to the variances within each database.
Many databases present subject headings as assigned "tags" to citations. As part of term selection for systematic reviews, identification of these terms may be important for inclusion in the search strategies. Examples of databases with subject headings would be: