Evidence Based Concepts

Understanding the basic concepts used in EBDM builds the foundation for developing the necessary skills needed to use the process.  The following procedures provide an overview of the five steps and skills involved in establishing an evidence-based practice.

1.  Converting information needs/problems into clinical questions so they can be answered
Patients have increasing access to medical and healthcare information on the Internet and are becoming more informed healthcare consumers.  Therefore, the clinician's need to access new information and remain current with scientific findings is becoming more critical.  The evidence-based approach guides clinicians in structuring well-built questions that result in patient-centered answers and can improve the quality of care and patient satisfaction.

Asking the right question is a difficult skill to learn, yet it is fundamental to evidence-based practice.   The process almost always begins with a patient question or problem.   A "well-built" question should include four parts, referred to as PICO that identify the patient problem or population (P), intervention (I), comparison (C), and outcome(s) (O).⁴

2.  Conducting a computerized search with maximum efficiency for finding the best external evidence with which to answer the question
This type of search requires a shift in thinking.  Often, especially now with fast web-based search engines, health professionals can look for "something" on a topic, a quick answer, or for "everything." Finding relevant evidence requires conducting a very focused search of the peer-reviewed professional literature based on the appropriate methodology.

Using an evidence-based approach recognizes that clinicians can never be completely current with all conditions a patient may have and provides a mechanism for addressing these gaps in knowledge in order to provide the best care possible.  Online databases and software that enable quick access to the literature have made it easier to locate relevant clinical evidence.⁵ Knowing what constitutes the highest levels of evidence and how to apply evidence-based filters and limits will let you search the literature with maximum efficiency.⁶

It is the combination of technology and good evidence that allows healthcare professionals to apply the benefits from clinical research to patient care.⁵ When searching for evidence to answer a question or support decisions, it is important to not restrict the search to the literature within only one discipline.   Looking at only "dental" literature would severely limit the resources available on a specific topic that may be well documented in the medical, educational, pharmacological, nursing, public health, or allied health literature.

To assist professionals in keeping up with the literature and in making it possible to quickly find needed information without leaving your location, online access to MEDLINE, provided by the National Library of Medicine (NLM), is now available.  They also provide a free version of MEDLINE called PubMed that can be accessed at http://www.pubmed.gov.

What Constitutes the Evidence?
Scientific evidence is the product of well-designed and well-controlled research investigations.  A single research study does not constitute "the evidence" but rather contributes to a body of knowledge that has been derived from multiple studies investigating the same area.⁷ Thus, the body of evidence evolves over time as more research is conducted underscoring the importance of staying current with the scientific literature.   Once synthesized, this evidence can help you make informed decisions about whether a method of diagnosis or a treatment/intervention is effective relative to other methods of diagnoses or to other treatment/interventions and under what circumstances.

The use of evidence in practice is not new.  What is new is the nature of the clinical evidence itself in terms of the methods for gathering it [randomized controlled trials and other well-designed methods], the statistical tools for synthesizing and analyzing it [systematic reviews and meta-analysis], and the ways for accessing and applying it [electronic databases and EBDM].^8,9

Levels of Evidence
Unfortunately, there is not one central repository for oral health information or quality evidence.  Traditional sources of evidence include printed materials such as textbooks, personal journal collections, conference proceedings, and clinical guidelines, which may not be based on well-conducted research.   Colleagues and personal experience are a predominant source of information for treatment decisions as well as those considered experts in the field.^10-12 As valuable as these sources are, scientific evidence supplements these components in the EBDM process.  (Figure 1) Sources regarded as strong evidence include systematic reviews, individual randomized controlled trials (RCT), and well-designed non-randomized control studies. (Figure 2)¹³

      

The hierarchy of evidence is based on the notion of causation and the need to control bias.¹⁴ The highest level of evidence or "gold standard" is the systematic review and meta-analysis [or more than one human RCT].  These are followed respectively by randomized controlled studies, cohort studies, case-control studies, to studies not involving human subjects.¹³ Although each level may contribute to the total body of knowledge, "…not all levels are equally useful for making patient care decisions."⁶ As you progress up the pyramid, the number of studies and correspondingly, the amount of available literature decreases, while at the same time their relevance to answering clinical questions increases.  A graphical review of research methods and designs can be found at:  http://servers.medlib.hscbklyn.edu/ebm/2100.htm.¹³ Knowing which segment of the literature is appropriate for clinical decision-making and how to quickly retrieve this information is important to evidence-based practice.

Click Here To Navigate Within Article >> Abstract Introduction Evidence Based Concepts Evidence-Based Decision-Making in Action Applying the PICO Process Structuring the PICO Question Conducting an Evidence-based Search Secondary Sources of Evidence Practice Tips Conclusions References About the Authors
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Citation Number: Vol. 3, No. 3, Page 012