Practising Evidence-Based Dentistry (EBD)

The five-step approach to teaching EBD is a structured (stepwise) process for dealing with clinical problems

The Evidence-based approach is essentially a structured (stepwise) process for dealing with clinical problems. This stepwise approach encourages the use of the latest information rather that a reliance on techniques, materials and treatments learned years earlier.

There are five elements to the approach. Select each tab below to find out more:

  • Question: Developing a clear question based on the patients clinical problem.
  • Find: Finding the latest evidence through efficient searching for information.
  • Appraise: Critically appraising the evidence to assess its value.
  • Act: Acting on the evidence you find, if appropriate and relevant to the clinical situation to provide treatment for the patients.
  • Evaluate: Each aspect of your performance in this process can (and should) be evaluated and this is increasingly relevant with the development of continuing professional development.

A closer look at each of the five steps:

  1. Question

In practice it is a rare day when you are not faced with a need to know some new information about the prognosis, treatment or management of a condition. Turning these clinical problems into a well-built (answerable) clinical question is a key skill of evidence-based practice.

There are essentially two types of question:

Background questions

These ask for general knowledge about a disorder and have two main components.

  • A question root (who, what, how, when or why)
  • A disorder or specific aspect of a disorder (e.g. What causes dental caries? or What are the complications of root canal treatment?)

Foreground questions

These ask for specific knowledge about how to manage patients with a disorder and a good or well-constructed foreground question usually has four main elements:

Graphic of the PICO format. P: The type of patient or the problem of interest, I: The main intervention or exposure; this is commonly a treatment but it could be a diagnostic test, some prognostic factor etc. C: The comparison intervention(s) where relevant, O: The clinical outcome of interest

Commonly referred to as PICO or PECO format (e.g. in patients with tooth discolouration would home bleaching compared to placebo lead to whiter teeth?)

Resources

  1. Find

How to find evidence

We are constantly bombarded with information from a wide range of sources. Traditional sources of information (books, journals and colleagues) as with other sources have their limitations.

With the rise of the internet, an increasing number of electronic databases are available which can provide access to the best current evidence. The most widely available free database is Medline which can be accessed via the PubMed interface. Increasingly databases are providing explicit evidence; a good example is the Evidence-based Medicine reviews product from Ovid, which combines a number of electronic databases (Cochrane Database of Systematic Reviews, Best Evidence, Evidence-based Mental Health and Evidence-based Nursing, Cancerlit, Healthstar, Aidsline, Bioethicsline and Medline).

The Cochrane Library is  a collection of databases that contain different types of high-quality, independent evidence to inform healthcare decision-making.

  • The Cochrane Database of Systematic Reviews
  • The Cochrane Central Register of Controlled Trials (CENTRAL)
  • Cochrane Clinical Answers

The Cochrane Library is probably the best single source of reliable evidence about the effects of healthcare.

Structured approach to searching

In order to be really effective in searching for evidence, specific training or access to an information specialist is required. However, for a busy practitioner a quick structured approach is:
First define the question – then search for each of the following in turn:

  • Evidence-based Guidelines
  • Cochrane Reviews
  • Evidence summaries (e.g from Evidence-based dentistry Journals, The Dental Elf)
  • Medline – for appropriate studies to answer your question.

Relevant Links

Resources

Papers on searching from the Canadian Dental Journal series on Evidence-based Dentistry

Search filters

Databases

Search Engines

  • Epistemonikos – a collaborative, multilingual database of health evidence. It is the largest source of systematic reviews relevant for health-decision making, and a large source of other types of scientific evidence.
  • TRIP Turning Research into Practice – Excellent UK based meta-search engine

Other

  1. Appraise

Appraising the evidence

Almost all scientific studies are flawed and it would come as a surprise to some clinicians that some (perhaps most) published papers (ref 1) should be thrown in the bin rather than used to inform clinical practice.

Critical appraisal is a way of rapidly assessing published papers in order to sort out the relevant or valid papers from the poor quality or irrelevant ones.

Validity – is the degree to which the results of the study are likely to be true, believable and free from bias.

Bias – is any factor (other than the experimental factor) that could change the study results in a non-random way.

Critical appraisal is best carried out in a structured/standardised way using explicit criteria. Appraisal can help the clinician to assess:

  • Validity
  • Clinical importance
  • Clinical relevance

References

Resources

How to Read a Paper series (1997) by Trish Greenhalgh from The British Medical Journal

( In order to access these BMJ articles you will need to register with the BMJ )

Papers on appraisal from the Canadian Dental Journal series 2001

Study Design Series by Kate Ann Levin in the Evidence Based Dentistry Journal

Other

  1. Act

Acting on the evidence

Being aware of the available evidence is one thing, but acting on it is another.

There are a number of well documented delays between clinical practice and the available research evidence. The most often cited examples have been in medicine but one can look at the variations in the use of topical fluorides and fissure sealants despite good evidence of their effectiveness. These delays and variations in provision and uptake of treatments have contributed to the development of the evidence-based approach.

The practitioner needs to decide whether the specific patient is similar enough to those in the research to use the findings. There may also be barriers regarding the materials or equipment required, and there may also be cost implications. There are also personal barriers such as the extent to which the results conflict with professional experience and cherished beliefs (see list of resources below).

The decision to act on evidence should be based on the evidence, the relevance to your patient, the willingness of the patient to receive the treatment, and the practitioners ability to provide the treatment. It is therefore a carefully considered decision and not a ‘cookbook’ approach, as has been claimed by some opponents of evidence-based practice.

Resources for acting

Getting Research Findings into Practice Series from: The British Medical Journal (Now also available as a book)

  1. Evaluate

Evaluating your performance

The final step of the evidence-based approach is self-evaluation. In their Evidence-based Medicine textbook [1]. Sackett et al. suggest a number of self-evaluation questions for each stage of the evidence-based approach. A few examples are shown below:

  • Question
    • Am I asking any clinical questions?
    • Are they well structured?
  • Finding
    • Am I searching for evidence?
    • Do I know what the best sources are?
    • Am I getting better at it?
    • Am I finding evidence?
  • Appraisal
    • Am I critically appraising evidence?
    • Am I getting better at it?
  • Act
    • Am I using evidence I find and appraising it in my practice?

References

  1. Sharon Straus Paul Glasziou W. Scott Richardson R. Brian Haynes. Evidence-Based Medicine: How to Practice and Teach EBM. 5th Edition. Elsevier 2018.

Resources