Introduction

An essential skill for all professionals is using evidence in practice. Being able to determine the quality of research or information upon which evidence is based is a necessary skill for all midwives. Evidence-based healthcare should be the foundation for all policy decisions made within the health service and by midwives (DH 1997, 1999; 2008). Having the appropriate knowledge to evaluate research and evidence to assist in decision-making with women and families, appropriate to their individual needs, requires development of knowledge and skills with understanding of information, resources and women’s views.

Definition

At its most descriptive level, an evidence-based approach to healthcare involves basing decisions and actions on the best available evidence. Evidence-based healthcare (EBHC) can be viewed as a strategy, using a set of tools that enable practitioners to be aware of and locate the available evidence, judge its strength and soundness and be in a position to apply it in practice.

Central to the whole enterprise of EBHC is the concept of ‘evidence’; however, the term itself is confounded by complexity through different interpretations of its meaning.

What is evidence?

Evidence is a familiar concept within a legal context, where it has been defined as information which may be presented to a court of law, in order for a decision to be made about the probability that a claim is true. In other words, it is the information on the basis of which facts are proved or disproved (Keane 2008), where evidence is sought for the basis of clinical decision-making.

Judging what constitutes ‘sound evidence’ in healthcare can be problematic. Evidence can be drawn from a variety of sources:

While each of these may give rise to evidence which is adequate for making decisions in practice, they also have their limitations. Sources of evidence for practice are examined for their strengths and limitations.

Evidence used by a professional influences their decision-making in practice. The foundation for all decisions is the knowledge base of that professional. For forms of knowledge used in midwifery, see website. The knowledge base of a society is influenced by experts in the field (see website for expert opinions).

Hierarchy of evidence

The preceding section has considered the sources of evidence and knowledge forms (see website) used to inform clinical practice, indicating strengths and limitations of approaches.

The literature promoting an evidence-based approach to healthcare (see Gray 2001, Greenhalgh 2006, Sackett et al 2000, amongst others) suggests a hierarchical order of value for different sources of evidence. This places a hierarchy in order of:

Methods at the ‘top end’ of the above hierarchy are valued more highly because they have mechanisms built into them which are intended to counter bias (Fig. 5.1).

Figure 5.1 ‘Hierarchy’ of evidence.

(Adapted from Greenhalgh 2006)

However, it needs to be remembered that no one method is free from bias and therefore all evidence must be examined in a critical way before it can be used. Whilst personal experiences and knowledge are additional sources of evidence which should inform practice and research at every level, all evidence needs to be judicious in its use for each woman and baby and their individual context (Sackett et al 2000). Many issues requiring clinical decisions have not yet been studied in a systematic way and therefore personal experience and case reports remain important and essential in clinical decision-making (Walsh 2008).

What stimulates the search for evidence to use in practice?

The search for evidence may be generated when practitioners or service users try to challenge the perpetuation of traditional practices. Early research pioneers in midwifery used their findings to change practice and challenge traditions (Romney 1980, Romney & Gordon 1981, Sleep et al 1984). This may stem from the desire to confirm and disseminate personal approaches to clinical care (McCandlish et al 1998). Whilst it may arise from an interest in investigating the nature of midwifery practice, it may also be stimulated by the numerous debates that surround the provision of maternity care – such as antenatal care (Sikorski et al 1996), place of birth (Olsen 1997), nutrition in labour (Scrutton et al 1999), or midwifery-led care (Hatem et al 2008).

The two activities – conducting primary research to generate knowledge and critically appraising existing research findings – are closely linked. The further development of midwifery practice and care women receive depends on practitioners applying both of these activities in their professional lives with recurrent self-questioning of use of evidence to answer clinical questions.