Where to find the evidence

Ideally, clinical decisions will incorporate the most current and relevant scientific research, but where is the best place to search for the evidence base for veterinary medicine? Unfortunately, there is no “one-stop-shop”, and so a variety of search tools, databases and methods must be used.

The evidence that supports the clinical decision-making of vets is interdisciplinary and traverses veterinary and human medicine, biomedical sciences and applied life sciences – and so use of a number of different sources may be needed to get optimum coverage of the available evidence.


“Researchers in veterinary medicine depend on the literature of many complementary fields of study. The literature of the biological sciences, including laboratory and clinical science, is essential, as are most aspects of human medicine, since they overlap in varying degrees with veterinary medicine.” Youngen (2011)

The ways in which you can find evidence are outlined below, and more detail is provided throughout this chapter:

  • Look for synthesised evidence
    Evidence syntheses aim to provide comprehensive summaries of the best scientific evidence on targeted clinical practice topics.  They offer clinicians a quick and efficient way of getting a clinical bottom line for a given clinical question.  If you can find an evidence synthesis on your clinical question it is the ideal starting point for EBVM. However, they are still relatively rare and so you will often need to search for primary research.
  • Search the bibliographic databases, using the best that is available to you
    Bibliographic databases are tools designed to help you search across the research literature (journals, books, conference papers, etc.) by subject and author. They can focus on a particular subject area, or be inter-disciplinary.  Each database systematically indexes articles from a given list of scholarly and professional publications, and so provides the most efficient method for searching the scientific literature. If no secondary evidence already exists in a synthesis, then databases can help with a search of the primary research.
  • Review the references of relevant papers
    Citation searching allows you to explore references included in a paper, and also to identify subsequent papers that cite the paper of interest. Mining the reference list is fairly straightforward, but search tools such as Web of Science, Scopus and Google Scholar also allow you to follow a ‘citation map’ to see what other papers on the same topic were published after the one of interest.
  • Read key publications
    Hand-searching involves a manual page-by-page examination of journals, conference proceedings or books to identify relevant evidence. This may be an important source of evidence for veterinarians in practice, and also has a formal role to play when done systematically to identify trials that may not have been picked up by the bibliographic databases (Higgins and Green, 2011).
  • Contact researchers and experts
    Seeking and sharing expert opinion has been made much easier with Internet communication tools and social media, and these informal networks can be an effective means of gathering information (e.g. for requesting the full text of an article from the author directly).
  • Search the ‘grey’ literature
    Grey literature is material that is not formally published within the conventional, commercial publishing channels and so it will not always be captured by bibliographic databases. Examples include technical reports and working papers from government agencies or scientific research groups, dissertations and some open access material on the Web. Some may be accessible via Internet searches.
  • Use unpublished data
    Unpublished data, such as clinical records, practice guidelines and pre-prints of journal articles, can provide useful evidence. Traditionally, peer-reviewed scientific journals, and the bibliographic databases that index them, have been considered the best source of evidence. Research into publication bias (Glanville et al., 2015) suggests that there is a need to go beyond these sources alone, as a significant proportion of research will not be published in peer-reviewed journals. You may have access to conference papers or case reports, and it has been recognised that clinical records and practice data might be harnessed to help veterinary professionals make evidence-based decisions at the point of care (Lefebvre, 2014 and Brodbelt, 2014).

Vets need to try broad searches of the numerous available sources of evidence as the evidence may be archived in a number of different places within a number of disciplines.

The Internet has brought unprecedented access to information direct to the clinical setting, making it possible for a vast amount of information to be created, disseminated and accessed at great speed, potentially assisting with all of the techniques listed above. However, it can also make acquiring information problematic, as the complexity of the information landscape, the problem of information overload, and the barriers presented by expensive subscriptions to scientific information can be prohibitive.

Navigating the information landscape can seem quite daunting, but this section is designed to offer some practical advice to help.