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Inicio Cirugía Española (English Edition) Then, how do I document the idea? Bibliographic search engines
Journal Information
Vol. 100. Issue 6.
Pages 375-377 (June 2022)
Vol. 100. Issue 6.
Pages 375-377 (June 2022)
Methodology letter
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Then, how do I document the idea? Bibliographic search engines
Y ahora, ¿cómo documento la idea? Buscadores bibliográficos
Sonia Fernández-Ananín
Corresponding author

Corresponding author.
, Jesús Bollo Rodríguez, Eduardo M. Targarona Soler
Unidad de Cirugía Gastrointestinal y Hematológica, Hospital de la Santa Creu i Sant Pau, Universidad Autónoma de Barcelona, Barcelona, Spain
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Information is an essential instrument for the development of any professional, especially for those of us who work in the health sciences. Its application in a rigorous, solid and current manner allows us not only to advance in the scientific and academic field but also in our daily practice. The large volume of knowledge available today makes it necessary to design optimal bibliographic searches to discriminate data that are relevant and worth analyzing from those that should be excluded.

Creating an appropriate strategy for obtaining information is, without a doubt, a determining factor for the achievement of said objectives. It is essential to understand the different stages that constitute a bibliographic search, to know how to execute a timely strategy, and to know the databases and bibliographic managers available.

Stages in the process of a bibliographic search

To obtain beneficial results that will allow us to find answers to the question posed, different stages have been defined in the course of a bibliographic search1,2:

Properly formulate the clinical question to which we want to obtain an answer. The initial step in this process involves correctly and precisely formulating the question about which we want to obtain an answer that satisfies our need for information3. Different tools have been described that help define the structure of the question we want to ask. The classically used methodology is PICO, which divides the question into 4 components: Patient, Intervention, Comparison and Outcome4. Another search system is SPIDER (Sample, Phenomenon of interest, Design, Evaluation, Research type), which was specifically created to identify qualitative studies by adding the categories ‘design’ and ‘type of research’5.

Identify or choose the database or bibliographic search engines in which the question will be formulated. There are many databases and bibliographic search engines available that provide access to information. The specialization in a certain area, language, accessibility and type of access (free or subscription) are criteria that will determine the choice of one or the other.

Planning the search strategy and translating the question into the language of the selected database or search engine. In this stage, we must decide how to combine the chosen medical terms and which descriptors or medical subject headings (MeSH) to use. Likewise, the use of Boolean operators, which connect our selected search terms, will allow us to either narrow or broaden the search. Finally, we will use the limiting fields, which offer the possibility of selecting our results to carry out a more effective search strategy.

Formulating the search strategy and analyzing the results obtained. Sometimes it is necessary to modify the elements of the search and reinitiate it6.

Creation of the search strategy

In recent years, there has been a significant and exponential increase in the number of scientific publications. Therefore, it is essential to previously prepare a proper strategy as an essential part of the bibliographic search process. Logical or Boolean operators should be included in this search strategy7,8. These operators form the basis of logical or mathematical sets that link search words to narrow, widen, or define results. There are 3 basic Boolean operators: AND, OR and NOT or AND NOT.

Also, to build a more complex search strategy, different Boolean operators can be combined using parentheses and quotes. The parenthetical command is performed first, and in all cases the operator used must be separated from the preceding and succeeding terms.

Bibliographic searches in healthcare sciences

There are numerous varied resources available for health professionals to obtain information. In biomedicine, there are currently various databases and search engines that provide access to information for consultation in an agile and dynamic manner9.

Databases are systems for collecting scientific-academic content publications (primary articles, review articles, books, theses, and communications at medical congresses) that contain relevant, updated, reviewed and proven information, whose purpose is to compile the bibliographic production of a specific field knowledge. Several online databases are available for the health sciences. The most commonly used include MEDLINE, EMBASE (Excerpta Medica DataBASE) and The Cochrane Library. In Spain, the IBECS (Spanish Bibliographic Index of Health Sciences), MEDES (SPANISH MEDICINE) and Dialnet (Dissemination of Alerts on the Network) are also used10.

In turn, bibliographic search engines are search managers used to access different databases with the purpose of selecting certain citations and references.

PubMed is the most widely used and well-known bibliographic search engine in biomedicine. This free-access search engine was developed in 1997 by the National Center of Biotechnology Information at the US National Library of Medicine. Since then, it has undergone numerous changes and improvements that have led to an exponential increase in its use, which now includes more than 32 million citations from the biomedical literature11,12. The main component of PubMed is the MEDLINE database, in which it is possible to execute both simple searches and other more elaborate ones through the use of limiters or MeSH to obtain more precise results13. Currently, it meets the needs of the millions of health professionals who demand updated and verified information on a daily basis.

In addition to the popular PubMed, there are many others such as Google Scholar, Ovid, Web of Science (WOS), Science Direct, Springer Link, etc. In 201714, Falgas et al analyzed the results of their study in which they compared the characteristics between PubMed, Scopus, WOS and Google Scholar and indicated that PubMed continues to be the most important resource for doctors and researchers (Table 1).

Table 1.

Characteristics of the main databases and bibliographic search engines.

  Year of creation  Country of origin  Sistema of the resource  Entity of production  Main language  Field of interest  Access method 
MEDLINE  1966  USA  Database  National Library of Medicine  English  Health sciences  Free access 
EMBASE  1974  Netherlands  Database  Elsevier  English  Biomedicine, pharmacology  Subscription 
Cochrane Library  1992  UK  Database  Cochrane  English  Health sciences  Free access 
Scopus  2004  Netherlands  Database  Elsevier  English  Sciences, technology, medicine and social science  Free access 
IBECS  2000  Spain  Database  Instituto de Salud Carlos III  Spanish  Health sciences  Free access 
MEDES  2001  Spain  Database  Fundación Lilly  Spanish  Health and social sciences  Free access 
Dialnet  2001  Spain  Database  Fundación Dialnet (University of La Rioja)  Spanish  Sciences; human, legal and social sciences  Free access 
PubMed  1996  USA  Search engine  National Library of Medicine  English  Health sciences  Free access 
Google Scholar  2004  USA  Search engine  Google  English  Scientific-academic documents  Free access 
Ovid  1984  USA  Search engine  Wolters Kluwer Health  English  Health sciences   
Web of Science (WOS)  2004  UK  Search engine  Clarivate Analytics  English  Sciences, social sciences, arts and humanities  Subscription 
Science Direct  1997  Netherlands  Search engine  Elsevier  English  Engineering and physical sciences, life sciences, Health sciences, Humanities and life sciences  Subscription (Free access to abstracts) 
Springer Link  1996  USA  Search engine  Springer  English  Sciences, technology, medicine, humanities, life sciences  Subscription 

In a global manner, information can be defined as the result of the analysis and treatment of data so that they respond to previously established questions. In biomedicine, accurate and current information enables us to advance, not only in scientific and academic fields, but also in our daily practice, as it is a powerful tool for evaluating, planning and managing resources.

Given the vast amount of knowledge generated and the multitude of data sources, search engines are required to encompass the greatest amount of verified information in a structured manner, using a simple interface.

Conflict of interests

The authors have no conflict of interest to declare.

Appendix A
Supplementary data

The following is Supplementary data to this article:


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J.S. Blumenthal-Barby, H. Krieger.
Cognitive biases and heuristics in medical decision making: a critical review using a systematic search strategy.
Med Decis Making, 35 (2015), pp. 539-557
C. Begg, M. Cho, S. Eastwood, R. Horton, D. Moher, I. Olkin, et al.
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Please cite this article as: Fernández-Ananín S, Bollo Rodríguez J, Targarona Soler EM. Y ahora, ¿cómo documento la idea? Buscadores bibliográficos. Cir Esp. 2022;100:375–377.

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