A practical guide for incorporating evidence into dental hygiene practice.

Overview

Treatment provided by dental hygienists has a substantial research base, which is grounded in caries prevention, periodontal disease prevention and treatment, public health, oral health education and health promotion. A simple search of the PubMed database in these areas identified over 100,000 citations. Given this wealth of scientific information, evidence-based decision making (EBDM) helps practitioners identify what is relevant so that it can be incorporated into practice.

Recognizing that clinicians have time constraints and yet want to provide the best possible care to their patients, an evidence-based approach offers clinicians a convenient method of finding current research to support clinical decisions; answer patient questions; and explore alternative treatments, procedures or materials. It also requires understanding new concepts and developing new skills, which just now are beginning to be integrated into curricula and practice. EBDM skills can be difficult to acquire, and it takes time and practice to become proficient. Understanding that busy practitioners cannot possibly master the skills necessary to use EBDM from one short article, the following article will provide: 1) an overview of EBDM concepts and skills, 2) a guide for finding the evidence and 3) a listing of online evidence-based resources that can assist in developing EBDM skills.

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Evidence-Based Concepts and Skills

What Is Evidence-Based Decision Making?

Evidence-based decision making (EBDM) is defined as the formalized process of using the skills for identifying, searching for and interpreting the results of the best scientific evidence, which is considered in conjunction with the clinician's experience and judgment, the patient's preferences and values, and the clinical/patient circumstances when making patient care decisions. (1) EBDM is not unique to medicine or any specific health discipline, but represents a concise way of referring to the application of evidence to the decision-making process. The use of current best evidence does not replace clinical expertise or input from the patient, but rather provides another dimension to the decision-making process that is also placed in context with the patient's clinical circumstances (Figure 1).

Principles of EBDM and Levels of Evidence

EBDM is about solving clinical problems and involves two fundamental principles:

1. Evidence alone is never sufficient to make a clinical decision, as was discussed in the definition of EBDM, and

2. A hierarchy of evidence exists to guide clinical decision making (2) so that the highest level of evidence is considered for a given question.

The hierarchy of evidence is based on demonstrating that the intervention or treatment caused the effect and the ability to control or minimize bias (Figure 2). (3,4)

The highest levels of evidence or "gold standard" for treatment questions are the systematic review and meta-analysis (synthesis of two or more randomized controlled trials [RCTs]). Also considered "level 1" evidence is an individual RCT. These are followed respectively by cohort studies (level 2), case-control studies (level 3) and case reports (level 4), followed by studies not involving human subjects. (5) An excellent short graphic review of each of these research methods and designs can be found at the SUNY Downstate Medical Center, Evidence Based Medicine Course, Guide to Research Methods--The Evidence Pyramid (6) available at http://servers.medlib.hscbklyn.edu/ebm/2100.htm

Systematic reviews (SRs) and meta-analyses (MAs) are considered the gold standard for evidence because of their strict protocols to reduce bias and to synthesize and analyze already conducted studies that address the same question. A meta-analysis is a statistical tool commonly used with SRs, which involves combining the statistical data from the individual studies and conducting another analysis of the combined data. When the data are pooled from individual studies, the sample size and power usually increase. As a result, the combined effect can increase precision in estimating the effects of treatment. (7)

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SRs and MAs facilitate decision making by providing a clear summary of the current state of the existing evidence on a specific topic. With over two million articles published annually, SRs provide a way of managing large quantities of information (3) and make it easier to keep current with new research. SRs also support the development of guidelines by putting together all that is known about a topic in an objective manner. Most recently, evidence-based (EB) methodology was used by the American Heart Association to update the "Guidelines for the Prevention of Infective Endocarditis," (8) by the ADA for the "Guidelines on Professionally Applied Topical Fluoride: Evidence Based Clinical Recommendations" (9) and by the Canadian Dental Hygienists' Association for its guidelines on toothbrushing and on commercially available OTC rinsing products. (10)

Although they are a secondary source of information, because they synthesize already conducted research, SRs contain clear descriptions of the aims of the review, the material and methods, and a summary of the individual and combined results of the studies. (7) Systematic reviews include evidence from RCTs as well as other well-controlled methods. As valuable as SRs can be, their usefulness and the strength of the evidence derived from the SR depends on the quality of the previously published original studies (i.e., their ability to meet the eligibility requirements for inclusion in the SR). (7,11)

Although each level of the hierarchy may contribute to the total body of knowledge, or a continuum of knowledge, "... not all levels are equally useful for making patient care decisions." (4) As you progress up the pyramid, the number of studies and the amount of available literature decreases, while at the same time their relevance to answering clinical questions increases. Recognizing the level of evidence that you have is important to EB practice.

EBDM Skills and the Five-Step Process

EBDM requires developing new skills, such as the abilities to find, critically appraise and correctly apply current evidence from relevant research to decisions made in practice so that what is known is reflected in the care provided. Translating these skills into action include the five steps outlined in Table I. The focus of this article, however, is on skill 2, conducting a computerized search, specifically using PubMed Clinical Queries.

Distinctions Between Research and 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. (13) Thus, the body of evidence evolves over time as individual research studies are conducted, underscoring the importance of staying current with the scientific literature. Once individual studies are synthesized, the 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.

Distinguishing Characteristics of EB Publications

The popularity of the term "evidence-based" has resulted in numerous articles using this phrase in their title, or in identifying it as a keyword, and yet the article does not reflect the EB process. EB publications should have a structured abstract that identifies the specific objective of the study, the search strategy, selection criteria, data collection and analysis, main results and conclusions. Table II outlines the EBDM process and how it should be reflected in an EB article.

More confusion can be seen between SRs and literature reviews. Systematic reviews concentrate on answering a specific clinically focused question, making them narrower in scope than a literature review. A multidisciplinary team of experts in a given area generally conducts the review. (7) They use formal and explicit methods, and specify criteria for including or excluding studies in the review, which is designed to reduce bias. The methods used to conduct a systematic review surpass what can reasonably be expected of any one individual.

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In contrast to SRs, traditional literature or narrative reviews are generally directed by an individual using personal experience to define the hypothesis or research question, and select and summarize the literature. The traditional approach deals with a broad range of issues on a given topic rather than answering a specific question in depth. For example, a very specific question answered in a SR would be, "Is fluoride varnish more effective in preventing root caries as compared to topical SnF fluoride?" whereas a broad question in a literature review would be, "What measures are available for preventing root surface caries?" The broad review could include many types of fluorides and may not make comparisons between methods. Also, it is less systematic and more subjective, in that pro-established criteria for selecting literature are not specified. (14) Finally, a literature review does not combine data or statistically analyze it.

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A Guide for Finding the Evidence

It takes time to develop the skills for identifying, searching for and interpreting the results of the best scientific evidence on your own. Sources that clinicians can begin to use immediately are PubMed Clinical Queries, the Cochrane Collaboration, and EB journals.

PubMed Clinical Queries

The MEDLINE database with free access through PubMed (http://pubmed.gov), gives you quick access to the literature with out leaving your location and makes it easier to locate relevant clinical evidence (15) and keep up-to-date (Figure 3). Finding relevant evidence quickly is often difficult for practitioners without formal EB training. Fortunately, there is a short cut to accessing relevant evidence. The PubMed "Clinical Queries" feature uses EB filters to quickly and effectively access relevant articles for you when you type in a main topic (Figures 4 and 5). For example, when typing "fluoride varnish" into PubMed without using the Clinical Queries feature, 470 citations were identified. This then required additional steps in order to limit them to the highest levels of evidence. The results of limiting the citations identified 9 MAs and 78 RCTs. In comparison, when using the Clinical Queries Systematic Review feature, which automatically searches for systematic reviews, meta-analyses, reviews of clinical trials, evidence-based medicine, consensus development conferences and guidelines, 19 citations were identified (Figure 6). Six of these were full-text articles. Consequently, it is much easier and faster to review 19 abstracts than 470, and hopefully some of the six full-text articles will answer your question. If so, these could be easily downloaded for incorporation into the clinical decision-making process. However, if you need a citation that is not full-text, it can be purchased online for a fee. For example, to purchase one of the identified SRs, "Pit and fissure sealants versus fluoride varnishes for preventing dental decay in children and adolescents," published by the Cochrane Collaboration, the fee is $25.00. For the article published in Acta Odontologica Scandinavica, "Professional fluoride varnish treatment for caries control: a systematic review of clinical trials," the fee is $32.00. If you would like more information about PubMed and the Clinical Queries feature, access their tutorial (Figure 7) at www.nlm.nih. gov/bsd/disted/pubmed.html.

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The Cochrane Collaboration

The Cochrane Collaboration is an international, volunteer nonprofit organization comprising academics, clinicians, researchers, industry representatives and journal editors who provide peer-reviewed systematic reviews that meet international standards. (16) All Cochrane Review groups have an obligation to update the review every two to four years to account for new evidence.

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The Cochrane Collaboration Oral Health Group has produced 74 SRs and is currently working on 66 protocols covering specific questions related to different fluorides and disease prevention interventions as well as on different general dentistry and dental specialty topics. The Cochrane Web site also provides a feature so that you can search for SRs related to your topic. For example, a search for fluoride varnish resulted in identifying five systematic reviews, Figures 8 and 9. These five also were identified in the PubMed Clinical Queries search discussed above.

A complete listing of all topics and their abstracts can be accessed free of charge from The Cochrane Collaboration Web site, www.cochrane.org/index.htm. To find those specifically related to oral health, go to www.cochrane.org/reviews/en/topics/84_reviews.html. The results of each group's work are housed in the Cochrane Collaboration that can be accessed online at www.cochrane.org. The full Cochrane Library is available on CD-ROM as well as online from Wiley InterScience at http://www3.interscience.wiley.com/cgi-bin/mrwhome/106568753/HOME for $285 per year. The CD-ROM is updated quarterly, with customers receiving new discs every three months.

EB Journals

EB journals are another resource for busy clinicians interested in incorporating evidence into practice. They are designed to simplify and streamline the EB process by publishing one- to two-page summaries of valid research studies from the biomedical literature that answer a specific clinical question. Two journals covering oral health topics are The Journal of Evidence Based Dental Practice (online at www.elsevier.com/wps/find/ journaldescription.cws_home/623234/description?navopenmenu =-2) and Evidence Based Dentistry, (online at www.nature.com/ ebd/index.html). Both are published online and have a hardcopy version. Each strives to notify its subscribers of current evidence with the goal being to provide a time- and cost-effective method of staying current with clinically important advances in practice. Both journals provide reviews of already published studies and of new original research articles that address specific clinical questions and whose results are most likely to facilitate decision making that results in better patient outcomes. Article titles concisely present the study results and include the question being investigated.

Questions that have been answered fall into several categories of interest to dental hygiene practice, including dental anxiety, dental caries, oral cancer, oral health promotion, oral medicine, pediatric dentistry, periodontology, preventive dentistry, primary care dentistry, special care dentistry and TMD. Finally, both journals provide expert commentary and value-added abstracts that clearly describe the article's relevance to clinical practice and offer an understandable explanation of differences between clinical value and statistical significance.

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Online EBDM Resources

There are several online resources for those who would like to learn more about EBDM and develop the five EBDM skills: asking good questions (the PICO process), conducting computerized searches with maximum efficiency, critically appraising the evidence, applying the results, and evaluating your performance of the EBDM process. Several of these resources have been mentioned in this article.

Conclusion

EBDM provides a strategy for improving the efficiency of integrating new evidence into patient care. Being able to search electronically across hundreds of journals at the same time for specific answers to patient questions overcomes the challenge to finding relevant clinical evidence when it's needed to help make well-informed decisions.

As EBDM becomes standard practice, individuals must be knowledgeable of what constitutes the evidence and how it is reported. Understanding EB methodology and distinctions between different types of articles, such as systematic reviews and literature reviews, allows the clinician to better judge the validity and relevance of reported findings. To assist practitioners with this endeavor, the PubMed Clinical Queries feature, Cochrane Collaboration Library and EB journals are available. By integrating good science with clinical judgment and patient preferences, clinicians enhance their decision-making ability and maximize the potential for successful patient care outcomes.

References

(1.) Forrest JL, Miller SA. Enhancing your practice through evidence-based decision making. J Evid Base Dent Pract 2001; 1:51-7.

(2.) Evidence-Based Medicine Working Group. Users' guides to the medical literature, a manual for EB clinical practice. Chicago: AMA, 2002.

(3.) Long A, Harrison S. The balance of evidence, evidence-based decision making. Health Services Journal, Glaxo Wellcome supplement 1995; 6:1-2.

(4.) McKibbon A, Eady A, Marks S. PDQ, evidence-based principles and practice. Hamilton, Ontario: B.C. Decker Inc., 1999.

(5.) Oxford centre for evidence-based medicine: levels of evidence and grades of recommendations, 1998. Available at www.cebm.net/ levels_of_evidence.asp.

(6.) SUNY Downstate Medical Center, Medical Research Library of Brooklyn. Evidence based medicine tutorial, SUNY guide to research methods. Available at http://library.downstate.edu/EBM2/contents.htm and The evidence pyramid and research designs. Available at http:// library.downstate.edu/EBM2/2100.htm. Accessed Oct. 1, 2007.

(7.) Mulrow CD. Rationale for systematic reviews. BMJ. 1994; 309:597-9.

(8.) American Heart Association. Guidelines for the prevention of infective endocarditis. Circulation, Apr. 19, 2007. Available at http://circ.ahajournals.org/cgi/reprint/CIRCULATIONAHA.106.183095. Accessed Oct. 1, 2007.

(9.) American Dental Association. Professionally applied topical fluoride: evidence-based clinical recommendations. J Am Dent Assoc 2006; 137: 1151-9.

(10.) Asadoorian J. CDHA position paper on commercially available over-the-counter oral rinsing products. CJDH; July-August 2006 40(4): 1-13. Available online at http://cdha.ca/content/newsroom/position statements.asp. Accessed Oct. 2, 2007.

(11.) Committee on Quality of Health Care in America, IOM. Crossing the quality chasm: a new health system for the 21st century. Washington DC: The National Academy of Sciences, 2000.

(12.) Sackett D, Straus S, Richardson W. Evidence-based medicine: how to practice and teach EBM. London: Churchill Livingstone, 2000.

(13.) Greenhalgh T. "Is my practice evidence-based?" Should be answered in qualitative, as well as quantitative terms. BMJ 1996; 313:957-8.

(14.) Sackett D, Haynes R, Guyatt G, et al. Clinical epidemiology: a basic science for clinical medicine. 1999; Boston: Brown & Company.

(15.) Rosenberg W, Donald A. Evidence based medicine: an approach to clinical problem-solving. BMJ. 1995 Apr 29; 310(6987): 1122-6.

By Jane L. Forrest, EdD, RDH, and Syrene Miller, BA

Jane L. Forrest, EdD, RDH, is the chair of the Division of Health Promotion, Disease Prevention & Epidemiology, and the director of the National Center for Dental Hygiene Research at the University of Southern California School of Dentistry, Los Angeles, Calif. She has received federal funding for grants related to training faculty, clinicians and researchers. The focus of one grant was to prepare faculty on how to integrate an evidence-based approach into curriculum. As part of that grant, the Evidence-Based Decision Making Web site was established (www.usc.edu/ebnet). Dr. Forrest is an internationally recognized author and presenter on evidence-based decision making (EBDM). She has served as the preconference workshop chair for both the First and Second International Conferences on Evidence-Based Dentistry and has two chapters published on EBDM, one in the 10th edition of Clinical Periodontology and one in the 2nd edition of Dental Hygiene Concepts, Cases and Competencies. She also is the lead co-author on a new book being published, Evidence-Based Decision Making: A Translational Guide for Dental Professionals. She is active in several national and international associations and serves on several editorial boards including the Journal of Contemporary Dental Practice, the Journal of Dental Hygiene, and as an associate editor for the Journal of Evidence-Based Dental Practice. She also is an invited peer reviewer for the Journal of Public Health Dentistry, Journal of Dental Education and Periodontology 2000.

Syrene A. Miller, BA, is involved in creating the Web site, "Evidence-Based News," and in developing curriculum materials for Faculty Development Institutes that teach health professionals and educators how to integrate an evidence-based approach. She also is the co-author with Jane Forrest, EdD, RDH, of a new evidence-based book scheduled for issue in March 2008 titled, Evidence-based Decision-Making: A Translational Guide for Dental Professionals. Miller has presented at national and international dental, dental hygiene and allied health conferences on integrating an evidence-based approach into education, practice and research, and on enhancing dental practice and classroom presentations through the use of Internet technology and PowerPoint.

Table I. Steps Needed to Apply
the EBDM Process (12)

1. Convert information needs/problems into clinical
questions so that they can be answered.

2. Conduct a computerized search with maximum
efficiency for finding the best external evidence with
which to answer the question.

3. Critically appraise the evidence for its validity and
usefulness (clinical applicability).

4. Apply the results of the appraisal, or evidence, in
clinical practice.

5. Evaluate the process and your performance.

Table II. Evidence-Based Decision-Making Process and an
"Evidence-Based" Article

   EBDM Process                         Evidence-Based
                                     Article Characteristics

Define the problem or patient-     Defines the specific problem/
centered question                  question of interest through
                                   explicitly stating the
                                   objective of the study

Search the literature to locate    * Describes the criteria for
valid evidence to answer the         including and excluding
question                             studies pertaining to their
                                     topic

                                   * Identifies databases
                                     searched, and methods for
                                     identifying non-published
                                     materials

                                   * Identifies search terms and
                                     strategy used for identifying
                                     studies

Critically appraise the evidence   Describes the research design,
for its validity and               analysis and data methods and
applicability                      how they were used in
                                   determining the conclusions

Correctly apply the evidence to    Describes probability of
decisions made about patient       outcomes through reporting
care                               Numbers Needed to Treat, p-
                                   value and Confidence Intervals

Evaluate findings and outcomes     Analyzes outcomes related to
of application                     the application of evidence
                                   to the specific problem

                    Evidence-Based Tutorials

Introduction to EBM, Duke          www.hsl.unc.edu/services/
University/UNC                     tutorials/ebm/index.htm

SUNY Downstate Medical Center,     http://library.downstate.edu/
Evidence Based Medicine            EBM2/contents.htm
Tutorial from SUNY Medical
Research Library of Brooklyn

PubMed Tutorial, National          www.nlm.nih.gov/bsd/disted/
Library of Medicine                pubmed.html

Evaluating Internet Sources &      http://www.lib.purdue.edu/
Sites: a tutorial, Purdue          ugrl/staff/sharkey/
University                         interneteval/

                 EBDM Skill Development Resources

Forrest IL, Miller SA.             http://www.thejcdp.com/
Evidence-Based Decision Making     issue011/index.htm
in Action, Part 1: Finding the
Best Clinical Evidence." J
Contemp Dent Pract, 2002 August;
(3)3: 010-026.

Forrest JL, Miller SA.             http://www.thejcdp.com/
Evidence-Based Decision Making     issue013/index.htm
in Action, Part 2: Evaluating
and Applying the Clinical
Evidence." J Contemp
Dent Pract, 2003;(4)1:42-52.

Forrest JL, Miller SA.             http://journals.elsevierhealth.
Enhancing Your Practice through    com/periodicals/ymed/issues#2001

Evidence-Based Decision            Series on EBDM skills
Making." Feature Series,           published in the Journal of
Journal of Evidence                Evidence Based Dental
Based Dental Practice, July        Practice.
2001;1:51-57.

  Forrest JL, Miller SA. "PICO,
    Learning How to Ask Good
    Questions." October
    2001;1:146-151.
  Forrest JL, Miller SA.
    Finding the Best Clinical
    Evidence. December 2001;
    1(3):227-236.

  "Analyzing the Evidence."
    June 2002; 2(2): 178-185.

Forrest IL, Miller SA. "Part I:    Not available online
the Anatomy of Evidence-Based

Publications: Article Summaries
and Systematic Reviews." Spring
2004, Dent Hyg 78(2):343-348.

Forrest JL, Miller SA. "Part       Not available on line
II: Manual versus Powered
Toothbrushes: A Summary of The
Cochrane Oral Health Group's
Systematic Review." Spring 2004,
Dent Hyg 78(2):349-354.

Forrest, Miller, Overman and       In production, Lippincott
Newman. EBDM: A Translational      Williams & Wilkins
Guide for Dental Professionals,
Spring 2008

               Research Design & Critical Appraisal Forms

Guide to Research Methods,         http://library.downstate.edu/
The Evidence Pyramid               EBM2/contents.htm
                                   http://library.downstate.
                                   edu/EBM2/2100.htm

Critical Appraisal Skills          www.phru.nhs.uk/Pages/PHD/
Programme (CASP)                   resources.htm

CONSORT (Consolidated Standards    www.consort-statement.org
of Reporting Trials)

QUOROM (Quality of Reporting       www.consort-statement.org/
of Meta-Analyses)                  QUOROM.pdf

                       Evidence-Based Centers

Evidence Based Decision Making,    www.usc.edu/ebnet
National Center for Dental         www.usc.edu/hsc/ebnet/
Hygiene Research, Resources        ebframe/ebbasics.htm
for Learning EBDM Skills

Agency for Healthcare Research     www.ahrq.gov/
and Quality (AHRQ), Evidence       www.ahrq.gov/clinic/epcix.htm
Based Practice Program

Centre for Evidence-Based          www.cebd.org
Dentistry

Centre for Evidence Based          www.cebm.net
Medicine

Centres for Health Evidence        www.cche.net

The Cochrane Collaboration         www.cochrane.org
Library

                  EB Databases and Publications

PubMed- Free public version        http://pubmed.gov
of MEDLINE

SUMSearch is a "meta-search"       http://SUMSearch.uthscsa.edu
engine for evidence-based          University of Texas Health
medicine resources.                Science Center at San Antonio

Evidence-based Dentistry Journal   www.nature.com/ebd/index.html

Journal of Evidence-based Dental   www.us.elsevierhealth.com/
Practice                           product.jsp?isbn=15323382

ADA Guidelines                     www.ada.org/prof/resources/
                                   positions/statements/index.asp

National Guideline Clearinghouse   www.guideline.gov

Point of Care Resources

Clinical Evidence                  www.clinicalevidence.com

Evidence Based On Call             www.eboncall.org/

Evidence Watch                     evidencewatch.com/

First Consult                      www.firstconsult.com

InfoPOEMS and InfoRetriever        www.infopoems.com

UpToDate                           www.uptodate.com/

The Trip Database, searches over   www.tripdatabase.com
61 sites of high-quality medical
information on the web.

Netting the Evidence access to     www.shef.ac.uk/~scharr/ir/
helpful organizations and useful   netting
learning resources

Drug Databases

* Corey Nahman.com updated Daily   www.coreynahman.com/
                                   druginfopage.html

* RxList                           www.rxlist.com

* MEDLINEplus Health Information   www.nlm.nih.gov/medlineplus/
                                   druginformation.html