1. Foundations in Evidence Based Practice B71P02
The Nature of Evidence
Welcome to this session on the Nature of Evidence which will lead on from your discussions of research approaches and help with preparation for Task 5.
Foundations in Evidence Based Practice
B71P02

2. Session Outcomes At the end of this session you will be able to:
Define Evidence Based Practice
Identify reasons for Promoting Evidence Based Practice
Identify nursing practice that might benefit from the use of evidence
Appreciate different forms of evidence

3. Definitions of EBP
Sackett et al (1996) define EBP as ‘ the conscientious, explicit and judicious use of current best evidence in making nursing decisions about the care of individual patients’
Carnwell defines EBP as ‘[the] systematic search for, and appraisal of, best evidence in order to make clinical decisions that might require changes in current practice, while taking into account the individual needs of the patient.’
She adds:
‘Best evidence might be defined as that which is valid and relevant to the patient.’ (Carnwell, 2001)
It may help therefore to review a number of definitions related to EBP in order to establish how evidence may be viewed in different ways.
The Sackett et al definition acknowledges that we should use the best evidence available; use the most current version of that evidence; but apply it judiciously in the context of individual patient care.
Carnwell also acknowledges the requirement to consider patient needs and that the nurse needs to be able to both search for and appraise evidence in order to make sound clinical decisions. She further adds that evidence must be valid and relevant to the individual patient. Your work to date in Task 1 has been about effectively searching for appropriate evidence. The reflective activity in Task 2 can be seen as one approach to appraising evidence based around a specific situation as it requires you to analyse and evaluate the experience i.e. to seek evidence to explain the situation and to understand it. This understanding in turn enables you to make clinical decisions.

4. Definitions of EBP
‘Clinical decisions should […] be informed by up-to-date, relevant and robust evidence rather than outdated primary training or over interpretation of individual patient experiences (Donald & Greenhalgh, 2000; Sackett et al, 2000) Use of best evidence is thus important.
This definition emphasises the need to seek current information; to assess the relevance of the information to the circumstances present at the time; and to appraise the rigour or robustness of the evidence.
It also indicates that we as nurses should be thinking about continual development of knowledge (that learning does not stop when you qualify) and that we should not attribute the experience of one patient to all others i.e. we shall not treat all patient’s similarly based on our experience of one.

5. Relevance of EBP to nursing practice
What areas of nursing practice might we want to ask EBP questions about? Discuss this with a partner.
If EBP is of relevance to nursing practice what aspects of practice might we want to ask questions about and seek evidence for? A starting point for you might be to ask yourself what don’t I know/what would I like to find out more about?

6. Relevance of EBP to nursing practice
You might ask questions about a range of categories of practice:
Assessment – how to properly gather and interpret findings?
Causes of the problem – how to identify them?
Deciding what the problem is – where the symptoms/signs indicate a range of possible problems how do you decide which is most likely?
How to select and interpret tests used to identify problems and to monitor patient progress?
How to estimate the likely clinical progression of a condition/illness and any likely complications?
How to select interventions that do more good than harm and that are worth the effort and cost of doing them?
How to reduce the chance of the problem reoccurring or how to promote health?
How to keep up to date; improve your skills; and run a more effective/efficient nursing team?
How best to understand the perceptions of individuals and groups e.g. service users and carers
Adapted from Sackett et al (1997)
( - Accessed 22/11/07)
We might thus want to ask questions about nursing procedures and practices as well as about specific illnesses or conditions. We might also wish to explore best practice from the perspective of service users or their carers or other key stakeholders such as service commissioners.

7. Why is best evidence and evidence based nursing important?
With a partner make a list of reasons why we should use evidence to underpin nursing care
What outcomes might we expect from using evidence based practice?

8. Why is best evidence and evidence based nursing important?
Ensures patient/clients receive the care that fits their needs
Facilitates sound decision making and makes it more explicit
Minimises risk to the patient/client so that benefits outweigh harm
Provides the nurse with the skills and knowledge to evaluate healthcare literature and practice
Exposes gaps in knowledge and conflicts in evidence
Here are some examples of outcomes – refer to slide.
Evidence from the NHS Litigation Authority:
2006/07 – 5,426 claims of clinical negligence
3,293 claims of non-clinical negligence
£579.3 million paid out in connection with clinical negligence (includes damages and legal costs)
£33.9 million for non-clinical negligence
Total = £613.2 million
(Legal costs = £132, 737, 180 million)
96% of cases are settled out of court. If a person has legal aid the Trust will pay their own legal costs even if they successfully defend the claim.
Total current liabilities £9.09 billion for clinical claims + £0.13 billion for non-clinical claims (figures include actual and projected claims). There were 18, 493 live claims as at 31/3/07.
Biggest areas for claims:
1 Surgery 2 Obstetrics & Gynaecology 3 Medicine 4 A & E. Nursing is 13th in the list – 67 claims since 1995.

9. What is Evidence?
In the context of evidence based practice this is research published in professional and academic journals and systematic reviews of research found in databases of evidence (such as Cochrane).
‘ Knowledge derived from a variety of sources that has been found to be credible’ (Higgs & Jones 2000)
Having considered the nature of EBP let’s look a little more closely at the nature of evidence itself.
A commonly held view is that evidence arises from well conducted research (either individual studies or systematic reviews of a body of research) which has been published and thus subject to external scrutiny.
Systematic reviews in particular seek to bring together knowledge derived from a number of credible sources and the credibility of the source is determined by specific inclusion criteria.

10. Evidence Classified by Level:
At least one systematic review of multiple, well designed randomised controlled trials (RCT’s)
At least one properly designed RCT of appropriate size
Well designed trials without randomisation, single group pre-post, cohort, or matched case controlled studies
Well designed, non-experimental studies from more than one centre or research group
Opinions of respected authorities, based on clinical evidence, descriptive studies or reports of expert committees
(Source: Muir Gray, 1997)
A number of frameworks are available to aid assessment of the strength of the evidence that we might have found. This is just one of them but it does help us to judge the credibility/worth of the evidence.
It is though biased toward research based evidence and arguably there are other forms of evidence that may be of use. What other sources of evidence might be available – where else other than from research might we obtain evidence? (see next slide for suggestions).

11. Other Forms of Evidence
Evidence based on experiences (professional or personal)
Evidence gathered from patients/clients and/or carers.
Evidence based theory that is not research based.
Le May (1999) ‘Evidence-based practice’ Nursing Times, Monographs, 1;2.
The first and second forms of evidence might form the basis of qualitative research (but not necessarily so) whilst the third is likely to arise from clinical practice or clinical experience or clinical expertise. The third encompasses theoretical ideas and concepts that are used to guide practice but which may not have arisen from research.
We will be addressing these different forms of evidence further in the next session.

12. What EBP is not EBP is not cook-book practice
evidence needs extrapolation to the patient’s unique biology and values
EBP is not cost-cutting practice
when efficacy for the patient is paramount, costs may rise, not fall
As a summary of this session we might argue the following:
When evidence has been produced we have to decide whether it is credible; relates to our practice; and meets the needs of service users.
EBP may offer cost-effective approaches to nursing practice but sometimes the most effective approach is not the cheapest. EBP is not about, as the saying goes, ‘doing things on the cheap’.

13. The Evidence Quiz Evidence is important to nurses because:
It minimises the risks to patients
You don’t need to think about your actions anymore because the evidence does that for you
It ensure that patients receive care based on robust research
It ensures that research journals stay in business

14. The Evidence Quiz Evidence may help to answer questions about:
Methods of nursing assessment
What time the evening meal arrives on the ward
Whether it is tasteful for Mr James to wear a thong on a mixed sex ward
How to select interventions that do more good than harm

15. The Evidence Quiz Robust Evidence may be obtained from: Google
Heat magazine
The Cochrane library
Wikipedia
CINAHL
Nursing Times

16. The Evidence Quiz
The strongest forms of evidence may be obtained from:
The Times newspaper
Systematic Reviews
The bloke at the chippy
Randomised Controlled Trials (RCT’s)

17. References
Carnwell, R. (2001) ‘Essential differences between research and evidence-based practice’, Nurse Researcher, Vol.8, No.2, pp
DoH (1997) The New NHS: Modern, Dependable, London, The Stationary Office.
DoH (1999) Making a Difference: Strengthening the nursing, midwifery and health visiting contribution to health and healthcare, London, Department of Health.
Donald, A. and Greenhalgh, T. (2000) A Hands-on Guide to Evidence Based Healthcare: Practice and Implementation, Blackwell Science, Oxford.
Le May, A. (1999) Evidence-base practice, London, Nursing Times Books.
Muir Gray, J.A. (1997) Evidence-based Health Care. How to make Health Policy and Management Decisions, Edinburgh, Churchill Livingstone.
Sackett, D.L., Rosenberg, W.M., Gray, J.A., Haynes, R.B. and Richardson, W.S. (1996) ‘Evidence based medicine: What it is and what it isn’t’, British Medical Journal, 312, 7023, pp
Sackett, D.L., Strauss, S.E., Richardson, W.S., Rosenberg, W. and Haynes, R.B. (2000) Evidence Based Medicine: How to Practice and Teach EBM, 2nd edn, Edinburgh, Churchill Livingstone.