- Sarah Jo Brown, RN, PhD
Editors—When the phrase “the best available research evidence” is used in the evidence-based practice literature, just what is meant? One answer is that the best research evidence consists of all available and relevant findings that were produced by scientifically sound studies. Although meta-analyses and integrative research reviews, which analyse collective evidence from all or at least many studies, are being published with increased frequency, there continues to be considerable focus on the appraisal and use of the findings of single studies.
Knowledge for practice formats based on single studies often have limitations including: (a) the full scope of evidence on the subject is not considered, (b) the findings presented are isolated from the findings of other studies on the issue, and (c) the findings are of limited value to practitioners. To illustrate these points, consider the abstract and commentary pertaining to the study on the relation between unintended pregnancy and intention to breast feed by Dye et al in the July 1998 edition of Evidence-Based Nursing. The topic of this study is of interest to practising nurses, and the findings provide important pieces of information. As the commentator notes, however, the issue of whether or not a pregnancy was intentional is just one among many factors influencing whether a woman breast feeds. As a result, the study findings by themselves have limited value to practitioners. In contrast, if the findings of Dye et al were integrated with findings from other studies about the factors that influence intention to breast feed or actual breast feeding behaviour, the Dye et al findings would contribute to a research-based knowledge picture that is clinically useful.
I would suggest that the main question of interest to practitioners with regard to this clinical issue is which factors are thought to influence breast feeding behaviour and which of these factors are strongly supported by research evidence? Additional questions include does the constellation of influencing factors change dramatically from culture to culture or among age groups? And can the actions of caregivers mediate social, psychological, and attitudinal factors? If the research evidence relevant to one of these questions was assembled and analysed, the knowledge picture created (synthesised, if you prefer) would be of considerable value to practitioners.
In summary, I am recommending that when possible, knowledge sources that distil research evidence for healthcare practitioners move beyond the appraisal of the findings of single studies to appraise collective evidence. Furthermore, the distillation of research evidence should be organised in ways that are useful to practitioners. Assembling and appraising all credible studies germane to a clinically meaningful question, is one way to produce accurate and vital research based knowledge.1
We would like to thank Sarah Jo Brown for her thoughtful letter and would welcome the views of other readers (we are currently developing a forum with more space for discussion on the EBN website). The Editors would not disagree with any of the views expressed; indeed, most of the people involved with Evidence-Based Nursing are also active participants in the Cochrane Collaboration and spend a good proportion of their time producing, maintaining, and disseminating systematic reviews of research. That said, there is currently a relatively small (although increasing) number of up to date systematic reviews relevant to nursing. Evidence-Based Nursing gives high priority to new and updated systematic reviews that have a message for nurses and we regularly abstract them. However, we think there will always be a need for bringing the best quality individual research studies to the early attention of nurses. Our collective experience of working closely with practitioners in identifying and answering clinical questions is often at variance with your example. Nurses regularly bring forward extremely focused questions of the kind are women with unintended pregnancy less likely to breast feed? As well as the more general what factors are thought to influence breast feeding?
We strive to ensure that the individual studies we abstract are set in the context of both current practice and the existing body of research evidence by our commentators (commentators are usually supplied with copies of relevant systematic reviews). We also use the Notebook and Implementation Forum sections of the journal to raise awareness of the need to look for systematic reviews to provide an evidence base for practice (see the Implementation Forum in this issue).
In summary, we think a mixed method approach to raising awareness among nurses about the strategies for research based practice, to raising the profile of the Cochrane Collaboration, and to disseminating high quality research is likely to be the most effective approach. We also congratulate Dr Brown on the recent publication of her excellent book on knowledge for healthcare practice.