2 Mesogeion Avenue , 115 27 Athens, Building C, 2nd Floor.
Tel: 0030 210-7702861
Fax: 0030 210-7702861
Databases in the internet with regard to the health sciences includes millions citations and the researchers have the chance to search and find the appropriate evidence or, in other words, information about research questions. PubMed is among the hugest databases with regard to the health sciences and moreover access to PubMed is free of charge, so that it is the most often used database. Access to PubMed is free of charge in the web page http://www.ncbi.nlm.nih.gov/pubmed/. Successful searching and finding of the appropriate citations in PubMed are determined to a large extent by the key-words that are used by the researchers. The Boolean operators AND, OR and NOT are very useful research choices in PubMed and their appropriate use increases substantially the validity of searching. In particular, when the operator AND is used, for the connection between key-words, then the following citations include all the key-words. When the operator OR is used, for the connection between key-words, then the following citations include at least one of the key-words. When the operator NOT is used, for the connection between key-words, then the following citations include the first key-word but not the second one. During the searching via PubMed, research filters may be used, improving substantially the searching. Comprehension and application of fundamental principles of searching the literature via PubMed is essential in researchers’ efforts to find reliable and valid evidence, in order to offer clinical care in a rational way.