Defining the process to literature searching in systematic reviews: a literature review of guidance and supporting studies

Abstract

BackgroundSystematic literature searching is recognised as a critical component of the systematic review process. It involves a systematic search for studies and aims for a transparent report of study identification, leaving readers clear about what was done to identify studies, and how the findings of the review are situated in the relevant evidence.Information specialists and review teams appear to work from a shared and tacit model of the literature search process. How this tacit model has developed and evolved is unclear, and it has not been explicitly examined before.The purpose of this review is to determine if a shared model of the literature searching process can be detected across systematic review guidance documents and, if so, how this process is reported in the guidance and supported by published studies.MethodA literature review.Two types of literature were reviewed: guidance and published studies. Nine guidance documents were identified, including: The Cochrane and Campbell Handbooks. Published studies were identified through ‘pearl growing’, citation chasing, a search of PubMed using the systematic review methods filter, and the authors’ topic knowledge.The relevant sections within each guidance document were then read and re-read, with the aim of determining key methodological stages. Methodological stages were identified and defined. This data was reviewed to identify agreements and areas of unique guidance between guidance documents. Consensus across multiple guidance documents was used to inform selection of ‘key stages’ in the process of literature searching.ResultsEight key stages were determined relating specifically to literature searching in systematic reviews. They were: who should literature search, aims and purpose of literature searching, preparation, the search strategy, searching databases, supplementary searching, managing references and reporting the search process.ConclusionsEight key stages to the process of literature searching in systematic reviews were identified. These key stages are consistently reported in the nine guidance documents, suggesting consensus on the key stages of literature searching, and therefore the process of literature searching as a whole, in systematic reviews. Further research to determine the suitability of using the same process of literature searching for all types of systematic review is indicated.Electronic supplementary materialThe online version of this article (10.1186/s12874-018-0545-3) contains supplementary material, which is available to authorized users.

A typology of systematic reviews for synthesising evidence on health care

“…The term “systematic review” as a corner‐stone of evidence‐based‐medicine is used synonymously with “review of evidence,” “comprehensive review,” “literature review” and “overview,” but without a clear definition of the process or associated terms . They all have objectives and features, such as goals, methods, and audiences that influence the interpretation and synthesis of the results, and several key stages that establish search strategies, select databases; seek supplemental “grey” sources of literature, manage the yield of references; and document the results and process of the search Consequently, from the objectives and features, I identify six review types, although with considerable overlap of features (Table ).…”

“…seek supplemental "grey" sources of literature, manage the yield of references; and document the results and process of the search 32 Consequently, from the objectives and features, I identify six review types, although with considerable overlap of features (Table 1).…”

“…52,76 Comprehensiveness and reproducibility are considered essential search objectives for reducing bias and enhancing confidence in search results, although they may be impractical objectives for most review methods beyond the rigorous controls of a meta-analysis. 32 Unless the search questions are tightly focused, comprehensive searches tend to yield large numbers of irrelevant citations, and increase the risk of bias from relevant but poor quality evidence. 2,77 Alternatively, searchers can heed the law of diminished returns by aiming for optimal rather than comprehensive yields.…”

Software-testing education: A systematic literature mapping

“…We should add that, although any secondary study like ours seeks to apply comprehensive search processes and measures to ensure that we are "not missing relevant [primary] studies" [72], one can only minimize the chance of missing related primary studies, and there is no absolute guarantee that we find all papers. Indeed, there are papers outside the SE discipline that focus on the issue of effectiveness of search approaches, e.g., [72][73][74]. For example, Cooper et al mention in [72] that: "… comprehensive literature searching is implicitly linked to not missing relevant studies".…”

The importance of the review of literature for scientific research

“…Способност да се опише и анализира објављена литература о теми и развију расправе и аргументи је значајан корак у истраживању. 6 Ефективно претраживање литературе је кључна фаза у процесу писања прегледа литературе, чији се значај често превиђа. Сматра се да ће систематично, организовано претраживање литературе, која ефикасно користи расположиве ресурсе, вероватније произвести и квалитетан рад.…”