What is a systematic literature search of multiple databases? – Pubrica

1. What is a Systematic Literature Search of Multiple Databases Dr. Nancy Agens, Head, Technical Operations, Pubrica sales@pubrica.com In Brief Systematic literature search requires to organize and confront the search process in a structured manner. Systematic literature search has a higher chance of avoiding differences and bias in a systematic review. The performed use of multiple databases for a systematic literature search is the following four databases, which are EMBASE, Web of Science Core Collection, MEDLINE, and Google Scholar. I. INTRODUCTION A systematic literature search is a process of searching literature in a structured and pre-planned manner, and it is considered to be a critical component of the review process as it demands careful consideration of search terms (See Table 1), selection of databases, systematic search studies, and the process requires to reflect on the search findings obtained during the process. Systematic search studies are aimed at identifying a transparent report of the research, and this process can make the readers know about the review, what was done to determine the report and how the collected evidence supports the systematic review. The primary advantage of using a systematic literature review has a higher chance of avoiding bias, and as well the process allows in enabling to identify the literature gaps in the primary or existing research. Thus, through preventing the risk of bias, the search studies become reproducible. To clearly understand this process, in a systematic review methodology section, the authors will list all the citations and databases used for collecting evidence such as PubMed, Web of Science, Embase and the journals that were used for systematic literature search. II. SELECTION OF RELEVANT DATABASES After choosing keywords for a systematic search study, now the author has to select the appropriate databases that give relevant research studies to the formulated question. See Also: What is the formulation of the research question in systematic review? There are a couple of different databases and search tools available for literature search, and at this point, it is always good to search in multiple databases that can supplement each other. The different databases include Bibliographical database will have everything about a topic, a person, a geographical area, institution, etc. Library databases: It reflects what can be physically and electronically found through one or more libraries. Journal databases: This database is commonly consisting of published journals from a specific supplier. Specialized databases: This database will have grey literature, conference papers, compositions, OA repositories, artefacts, etc. Another critical point is to focus on the subject area, rather than considering the physical location and the form of data and the author probably know the extensive databases within the subject area. Still, it is advised to check the data provided by the individual databases, so that the author can be aware of the database has a bias towards geographical literature difference. databases: This Copyright © 2020 pubrica. All rights reserved 1

2. To avoid such bias, the author need answers for the question includes Are there limitations different regions or languages, e.g. French, German, covered? Does the database has covered the past enough for your purposes? How quickly does the database gets updated regarding the registration of the recent literature? Does the database cover all the journals types, e.g. original research publications, rapid communication, review articles, and case studies, that are required? III. SELECTION OF KEYWORDS THAT SHOULD BE USED FOR THE SEARCH While making the selection of appropriate keywords for search strategy, it is not mandatorily required to use all the words from the formulated research question, and less essential words from the question can be removed from the search strategy to avoid unnecessary complications. concerning Russian, etc. Fig. 1: Schematic diagram for determining the optimal order of elements With the help of Fig. 1 keyword can be ordered by the importance and their specificity on a question to determine the best search strategy. By using this principle in choosing the keywords, for instance, keywords can be rated between specific and important to general and unimportant, as the rated keyword can be incorporated in the search strategy. Thus the general and unimportant keywords help in avoiding bias and overlapping elements. IV. A SEARCH OF MULTIPLE DATABASES In general, combined, or multiple database searches are defined as the search study across multidisciplinary reporting that carries its advantages, and it is for studies, mainly if your work is interdisciplinary. But it is highly recommended to use of multiple databases along with added search strategies (like developing search terms, controlled vocabulary terms, search Copyright © 2020 pubrica. All rights reserved 2

3. fields, phrase searching, search limits and making search syntax for different databases) to search relevant references for conducting a systematic review. A thorough search is mandatory to identify a large number of pertinent references which is necessary for a quality systematic review. The primary systematic review recommend using a different database for investigating. The Cochrane Handbook suggests using at least Cochrane Central, MEDLINE and EMBASE, to search controlled trials. Whereas, the Cochrane Collaboration guidelines, a systematic literature search should include all the research articles that match the eligible criteria irrespective of the language, sample size and journal influence. See Also: What is a Systematic Review? It is now clear that a comprehensive search should consist of multiple databases such as EMBASE, Medline, Ovid, Cochrane Controlled Trials Register, Google Scholar, Scopus and when appropriate to topic CINAHL (EBSCOhost), PsycINFO (Ovid), and Sport Discus (EBSCOhost) can be included. The registries also advised considering some grey literature to reduce the publication bias and websites, such as the World Health Organization International Clinical Trials Registry Platform be searched in finding relevant ongoing and recently completed studies. However, few works of the literature suggest that using multiple databases can be time-consuming and vigorous owing to the database-specific search strategies (such as choosing database-specific search terms, searching with keywords, searching for exact phrases, searching with subject headings and citation searching) and differences subject areas and proximity operators between interfaces. The advantage of multiple literature searches is that it can easily cover an extensive range of literature and it can also be perfect in the initial phases of your searching to find the suitable databases for your subject area. disadvantage is that the precision in the searches suffers to some extent as it cannot use the individual database‘s specialized search fields and specified subject terms. Moreover, it is the different vocabulary terms between databases that may obstruct translation and limited access, subscriptions make the process more tedious and challenging. V. VARIATIONS IN SEARCH TERMS During the search process, variations in search terms such as truncation, spelling differences opposites and abbreviations will be very helping in getting all the relevant search results. For example, truncation allows the researcher to search for words like therap* will thus retrieve therapy, therapeutic, therapies, etc. Every database contains a reference to published articles using both American and British English spellings, and many interfaces offer a particular word with a character to get related search results. For example, ―paediatric‖ or ―pediatric‖ can be searched as ―p?ediatric.‖ registries of Whereas the randomized and PubMed Ovid EBSCOhost Embase.co m ProQuest [tiab]1 Title/abs tract ().ab,ti. TI () OR AB ()2 ():ab,ti AB,TI() 2 3 All fields [All Fields] .af. ALL Copyright © 2020 pubrica. All rights reserved 3

4. Thesaur us term [mesh:noexp] …/ MH ―…‖ ‗…‘/de MESH(…) Includin g narrowe r [mesh] exp …/ MH ―…+‖ ‗…‘/exp MESH#(…) Combine d subheadi ng …/sh[mesh] exp …/sh MH ―…+/sh‖‗…‘/exp/dm MESH(… LNK ..) _sh4 [sh]5 .xs. or .fs.5 MW :lnk5 Free subheadi ng [pt]6 :it6 Publicati on type .pt. exp …/7 or PT RTYPE 6 Proximit y ADJn Nn NEAR/n- NEXT/n N/n Exact phrase ―double quotes‖ No quotes needed ―double quotes‖ ‗single quotes‘ ―double quotes‖ Truncate d phrase Use-hyphen* No quote* No quote* ‗single quote*‘ ―Double quote*‖ Truncati on End End/ mid End/ mid End/ mid End / mid / start Infinite * * or $ * * * 0 or 1 characte r — ? # — $1 ?8 1 characte r — # ? ? Added to database since yyyy/mm/dd:yyy y/mm/dd [edat]9 (or [mhda]) limit #N to rd=yyyym mdd- yyyymmd EM yyyymmdd- yyyymmdd [dd-mm- yyyy]/sd LUPD(yyyym mdd) Copyright © 2020 pubrica. All rights reserved 4

5. d10 Publicati on period (years) yyyy:yyyy[dp] limit #N to yr=yyyy- yyyy11 PY yyyy yyyy- [yyyy- yyyy]/py YR yyyy) (yyyy- 111 Record sets #1 S1 #1 S1 Table 1: Field codes for biomedical literature search in top used interfaces (Obtained from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6148622/) VI. TRANSLATION BETWEEN DATABASES Multiple database search had to be done to retrieve as many relevant references as possible and translating complicated and exhausting findings between databases will be time-consuming and burdensome. To overcome that burden and save time, Erasmus developed to find and replace method for biomedical and health science questions. Using the five different macros, a search can be translated relatively quick into eight significant databases, and the dotted lines represent databases that are used in less than 80% of the searches. University Medical Center Fig. 2: Schematic representation of translation between databases (Obtained from https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6148622/) In summary, a systematic review uses scientific methods in finding results from multiple primary research studies and a combination of various databases would Copyright © 2020 pubrica. All rights reserved 4

6. yield more publication journals than using an individual database, which can help to make accurate decisions. But there need to be ways to optimize using multiple databases and combinations to include all the relevant references in the systematic review. Few literatures suggest using a combination of databases, depending on the review topic or the area of research and majority of the literature states that searching one database may prove to be insufficient, thus leading to missing references. Pubrica provides support in writing a systematic review on biomedical or healthcare areas such as public health interventions, environmental interventions, adverse effects, clinical trials, and social interventions and offers you complete support across a variety of journals, publications, and books. Our technical expert team provides complete support from translating your concept to incisive report, and we will be with you through the entire publication stages. REFERENCE 1. Levay P, Raynor M, Tuvey D. The contributions of MEDLINE, other bibliographic databases and various search techniques to NICE public health guidance. Evid Based Libr Inf Pract 2015; 10:50– 68. 2. Higgins JPT, Green S. Cochrane handbook for systematic reviews of interventions: The Cochrane Collaboration, London, United Kingdom 2011 3. Whiting P, Westwood M, Burke M, Sterne J, Glanville J Systematic reviews of test accuracy should search a range of databases to identify primary studies. J Clin Epidemiol 2018 61:357–364. DOI:10.1016/j.jclinepi.2007.05.013 4. Higgins JPT GS Cochrane handbook for systematic reviews of interventions. Version 5.1.0 (updated March 2011). The Cochrane Collaboration, 2011. Available handbook.org/. 5. Bramer WM, Rethlefsen ML, Kleijnen J, Optimal database combinations for literature searches in systematic reviews: a prospective exploratory study. Syst Rev 2017; 6(1):245. 6. Wichor M. Bramer., et al., A systematic approach to searching: an efficient and complete method to develop literature searches, J Med Libr Assoc. 2018 Oct; 106(4): 531–541. DOI: 10.5195/jmla.2018.283 at: www.cochrane- Copyright © 2020 pubrica. All rights reserved 4