Developing a Comprehensive Search Strategy for Evidence Based Systematic Reviews

Abstract

Objective ‐ Within the health care field it becomes ever more critical to conduct systematic reviews of the research literature to guide programmatic activities, policy‐making decisions, and future research. Conducting systematic reviews requires a comprehensive search of behavioural, social, and policy research to identify relevant literature. As a result, the validity of the systematic review findings and recommendations is partly a function of the quality of the systematic search of the literature. Therefore, a carefully thought out and organized plan for developing and testing a comprehensive search strategy should be followed. This paper uses the HIV/AIDS prevention literature to provide a framework for developing, testing, and conducting a comprehensive search strategy looking beyond RCTs.Methods ‐ Comprehensive search strategies, including automated and manual search techniques, were developed, tested, and implemented to locate published and unpublished citations in order to build a database of HIV/AIDS and sexually transmitted diseases (STD) literature. The search incorporated various automated and manual search methods to decrease the chance of missing pertinent information. The automated search was implemented in MEDLINE, EMBASE,PsycINFO, Sociological Abstracts and AIDSLINE. These searches utilized both index terms as well as keywords including truncation, proximity, and phrases. The manual search method includes physically examining journals (hand searching), reference list checks, and researching key authors.Results ‐ Using automated and manual search components, the search strategy retrieved 17,493 articles about prevention of HIV/AIDS and STDs for the years 1988‐2005. The automated search found 91%, and the manual search contributed 9% of the articles reporting on HIV/AIDS or STD interventions with behavioural/biologic outcomes. Among the citations located with automated searches, 48% were found in only one database (20% MEDLINE, 18% PsycINFO, 8% EMBASE, 2% Sociological Abstracts).Conclusions ‐ Development of a comprehensive review of the literature requires searching multiple databases and methods of manual searching in order to locate all relevant citations. Understanding the project needs, recognizing the limitations and strengths of specific electronic databases, and being aware of other methods for developing and refining a search are vital in planning an effective and comprehensive search strategy. Reporting standards for literature searches as part of the broader push for procedurally transparent and reproducible systematic reviews is not only advisable, but good evidence based practice.