Letter to the Editor

Abstract

In this letter to the editor, an updated version of the Embase search filter is presented. The former version of the filter does not work adequately anymore, because of alterations in 'Emtree', the Elsevier life science thesaurus. A thesaurus is a hierarchically structured, controlled vocabulary for efficiently searching the database in question. The functioning of the search filter critically depends on the way in which the thesaurus terms are related to one another.As of January 2013, the Emtree term human/ is included in the Emtree term Chordata/, which in itself is part of the Emtree term animal/ (http://www.elsevier. com/online-tools/embase/emtree).Previously, the Emtree terms human/ and animal/ were in separate branches of the tree. As a consequence of the altered relation between human/ and animal/, the former version of the filter started to include all studies that used humans (and no other animals) as subjects, whereas the filter was intended to exclude exactly this type of studies.We have adapted the 'mode' in which the Emtree terms animal/ and Chordata/ are present in the search filter, so that the filter no longer automatically includes the purely human studies. The total number of records the updated search filter retrieves on its own (5,884,276) and in combination with a search strategy specific for the topic pancreatitis and probiotics (83) are similar to those in the original version of the filter (search date 3 May 2013). The new version of the search filter (version 2; 31 January 2013) can be found in Supplement 1 (see

A Systematic Search and Mapping Review of Studies on Intracerebral Microdialysis of Amino Acids, and Systematized Review of Studies on Circadian Rhythms

“…We extended our previous search strategy for microdialysis [20] by adding the terms “chemitrode”, “dialytrode”, “brain dialysis”, “intracerebral dialysis”, “intracranial dialysis”, “transcranial dialysis” and “implanted perfused hollow fibre”. We used previously published filters to identify animal studies [2122]. …”

Evaluating mesenchymal stem cell therapy for sepsis with preclinical meta-analyses prior to initiating a first-in-human trial

“…Although MSC terminology has been codified (Dominici et al, 2006) non-standard terms continue to be used in the literature, thus a number of MSC related terms were used in the search strategy. Validated animal filters were applied to increase relevancy (de Vries et al, 2014; Hooijmans et al, 2010); post-hoc, an inadvertent truncation was noted in the application of these filters, thus an updated search was performed to include the complete filters. We searched Ovid MEDLINE In-Process and Other Non-Indexed Citations, Embase Classic+Embase, BIOSIS and Web of Science (using Web of Knowledge) from inception until May 2015.…”

Systematic Review and Meta-Analysis of the Efficacy of Interleukin-1 Receptor Antagonist in Animal Models of Stroke: an Update

“…We searched PubMed, Embase, BIOSIS and Web of Science Core Collection for [(interleukin 1 receptor antagonist) OR (IL-1 RA) OR (IL1RA) OR (IL1-RA) OR (Anakinra)] AND [(stroke) OR (ischemia) OR (cerebrovascular) OR (middle cerebral artery) OR (MCA) OR (ACA) OR (anterior cerebral artery) OR (MCAO)] AND [(Hooijmans et al PubMed animal filter [17]) OR (de Vries et al Embase animal filter update [18])] NOT [(coronary) OR (myocardial)]. We restricted the date of publication to post-2005, and the search was completed in February 2016.…”