Systematic review authors will be well aware of the critical importance of getting the search strategy "right" for the overall outcome of any systematic review. Getting it "right" takes time and even some research into what we are trying to achieve. Those of us who have worked on systematic reviews should appreciate the need to not only consider the appropriate keywords and search strings or filters within the various databases, websites and search platforms, but also the need to identify the most appropriate places to search. On the latter, I'd like to highlight two common issues we at the editorial team of the JBI Database of Systematic Reviews and Implementation Reports often encounter regarding where to search and how this is presented in protocols and subsequent systematic reviews.

Statistical shenanigans aside, a comprehensive search is the most effective way to limit the risk of publication bias impacting the results of the review and their subsequent impact on policy and practice. Whilst review authors must aim to maximize the comprehensiveness of their search strategy and search as many sources as feasible, time invested researching the scope and content of databases and resources is generally time well spent during the development of the review protocol. Determining which resources contain studies or information that are directly aligned to the review question may lead to looking in less places to find more relevant results - maximizing both the sensitivity and specificity of the search results.

The JBI approach to a comprehensive search strategy has always insisted on searching major bibliographic citation databases, for example, Medline, CINAHL and Embase, as well as other relevant resources including potential repositories of grey literature. The databases mentioned are some of the largest and most well-known citation databases in the health sciences and generally return good "bang for your buck" when searching for health-related literature. Searching across these major databases has generally been well aligned to JBI reviews of effectiveness and also those exploring the meaningfulness or experiences of interventions or therapies. Despite this, this prescriptive advice to database searching, whilst useful, still needs to be considered by review authors. As an example, increasingly review authors indicate their intention to search the Elsevier database Scopus. Scopus includes all of the citations in Medline and Embase from 1996 onwards, increasing the likelihood of duplicate citations in the search results that will require subsequent sorting by the review team. For any question, review authors should be well aware of the extra content indexed in Scopus and determine whether it is relevant to their review question prior to including it amongst the resources to be searched. Similarly, a qualitative JBI review would appear to gain no added benefit from searching the Cochrane Library, which is yet to index any primary qualitative literature stipulated in the inclusion criteria for meta-aggregative reviews. Searching these extra resources for these reviews will only increase the overall time taken to conduct the search and reduce the specificity of the approach, irrespective of how relevant the keywords and other search terms used are. Furthermore, as JBI review methodologies have developed to accommodate different types of questions and different types of study designs, this "standard" approach may not be appropriate for all JBI reviews. A JBI Umbrella review1, for example, will ideally target repositories of systematic reviews, such as the Cochrane Library and JBI Database of Systematic Reviews and Implementation Reports, while a review addressing a question related to costs of a health care intervention would not need to search the entire Cochrane Library, but rather only the National Health Service Economic Evaluation Database - which can still be searched by the interface of the Cochrane Library.

The second issue worth highlighting is the clarity with which resources used for searching for evidence are described and presented in review protocols and systematic reviews. Authors should be clear on what tools and resources they are using and why they are using them; protocols published in the JBI Database of Systematic Reviews and Implementation Reports are required to list databases and other sources where authors intend to search for relevant information and this information should be conveyed just as clearly to the reader. Submissions to the journal however often create more confusion for the informed reader rather than clarity. To illustrate the point, the majority of protocols submitted to the journal still tend to describe tools such as Mednar and Google Scholar as other relevant databases to search for added information. Neither of these resources is a database. Google Scholar, like Google, is a web search engine that searches across a range of sources including academic publishers and universities with keywords and search terms entered. Similarly, Mednar is also not a database, but rather a federated search engine that searches across a range of sources and databases simultaneously. On the practical side of the review process, ideally authors should review all of the "sources" available in the "Advanced Search" function of Mednar before conducting the search to determine if all of the sites Mednar searches are relevant to the review question. Considering the impressive range of sources, it is highly unlikely that all will be relevant to any one review, and some small investment of time in the planning stages of the search may save an enormous amount of energy when it comes to study selection and sorting the results of a comprehensive search for the evidence.

The Editorials presented through 2015 will continue to raise important issues and points for review authors to consider in the conduct of their review work. We hope you enjoy reading the current issue and forthcoming issues of Volume 13 of the JBI Database of Systematic Reviews and Implementation Reports.

Director, Synthesis Science, The Joanna Briggs Institute Editor, JBI Database of Systematic Reviews and Implementation Reports

References