2. What sources of evidence are there?
3. What sources of evidence are there?
Where can evidence be found to help answer clinical questions?
EBVM links the results of research to the practice of veterinary medicine, so we need to know where to find the best, most relevant research for each clinical question.
It is helpful to understand the difference between primary and secondary sources, and between published information and grey literature:
1. Published scientific research
Primary sources of evidence offer a first-hand account of research or practice written by those who were directly connected to it. In EBVM this typically means journal articles, reports or conference papers that describe:
- research studies (quantitative and/or qualitative)
- clinical trials
- case studies and case reports.
Secondary sources are created later by third-party authors who summarise or synthesise primary sources and often comment on them. These are discussed in more detail in the Secondary sources section and include:
- evidence syntheses (including systematic reviews, meta-analyses and evidence summaries e.g. Knowledge Summaries)
- clinical practice guidelines
- textbooks and manuals.
2. Grey literature
Grey literature is research material that is not formally published within the conventional, commercial publishing channels. Examples include:
- reports and working papers (e.g. from government agencies)
- theses and dissertations
- lecture notes
- websites, blogs and social media posts.
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bias (Glanville et al., 2015) suggests a need to go beyond these sources alone, as a proportion of research will not be published in peer-reviewed journals.
You may have access to books, conference papers or case reports…and clinical records and practice data are already being used to help veterinary professionals make evidence-based decisions at the point of care (Brodbelt, 2014).
The key is to use the best evidence available to you.