There are differing views on what is meant by the term ‘evidence’ and its value, types and sources in the context of evidence-based health care. [1,2] The Canadian Health Services Research Foundation (2005) developed the following definition that reflects many considerations around evidence.
Evidence is information that comes closest to the facts of a matter. The form it takes depends on the context. The findings of high-quality, methodologically appropriate research are the most accurate evidence. Because research is often incomplete and sometimes contradictory or unavailable, other kinds of information are necessary supplements to or stand-ins for research. The evidence base for a decision is the multiple forms of evidence combined to balance rigour with expedience – while privileging the former over the latter. 
Palliative care is a rapidly evolving, multidisciplinary field of practice. The types of evidence and knowledge produced within palliative care are accordingly varied and encompass many different types of research methodologies. Specific problems in research in the palliative care setting make some research exceedingly difficult to do, so that some study designs we might like to use to answer important questions relating to practice may never be available to us. The broad definition of the concept of evidence provided by Canadian Health Services Research Foundation accommodates the needs of palliative care.
An evidence-based approach is one which turns to the evidence to answer clinical and service-related questions and uses the best available evidence to do so. It involves appraising the quality of the evidence being used and acknowledges the strength of the evidence for decision making.
In practice, this means that CareSearch:
Read the US based National Cancer Institute's statement on palliative care evidence
Read this article on thinking outside the box for palliative care evidence
Visit McMaster University to learn about the 6S Pyramid for clinicians
Page updated 06 April 2022