Finding the Evidence
The evidence needed in an EBP effort may be found in a variety of sources, from computerized bibliographical databases to your own quality improvement department. In trying to find evidence, nurses are urged to get help. For one reason, finding evidence is very time consuming even when done with maximum efficiency and (theoretically) the more persons involved, the less any one person has to do. And second, those familiar with a method may search and find better sources of information.
A Systematic Approach to Finding Evidence
- Have a clearly defined topic (What specific question is being asked? What specific clinical problem is to be solved?).
- Review all existing hospital/agency policies/procedures for current practice standards (What is the recommended practice? Is this happening? What is the basis for the recommended current practice?).
- Determine if the recommended practice is being implemented. Quality improvement data may give you this information or a QI project may be needed.
- Check for external standards/policies on the topic (Are there existing clinical practice guidelines on the topic?)
- Find any systematic or integrative reviews on the topic or meta-analyses (See Critique). Depending upon the currency and completeness of systematic review(s) found, you may or may not choose to go to step 6, although it is recommended whenever possible.
- Search for primary research literature using one of the computerized bibliographic databases described below.
Computerized Bibliographic Databases
If you are a novice in doing searches, when possible, get assistance from a librarian. If this is not possible, the resources below may be helpful.
MEDLINE® is the National Library of Medicine's bibliographic database. It covers the fields of medicine, nursing, dentistry, veterinary medicine, the health care system, and the preclinical sciences. MEDLINE® contains bibliographic citations and author abstracts from more than 5,000 biomedical journals published in the United States and 70 other countries. The file contains over 18 million citations dating back to the 1966. Coverage is worldwide, but most records are from English-language sources or have English abstracts (US National Library of Medicine, 2010). MEDLINE® can be accessed without charge as PubMed®.
(Cumulative Index of Nursing and Allied Health Literature) is oriented towards nursing and allied health but also accesses biomedical and consumer information. Most English-language nursing journals are indexed along with journals in multiple allied health fields. Unique to CINAHL® is coverage of books and book chapter, pamphlets, standards of professional practice, conference proceedings, educational software, audiovisuals, nurse practice acts, critical paths, research instruments, legal cases, accreditation records, and clinical innovation integrative reviews. The database covers records from 1982 to the present. CINAHL® is not a free service but may be available through your organization or school's library.
The Cochrane Library includes several databases. One of them, The Cochrane Database of Systematic Reviews, contains Cochrane reviews and another, The Cochrane Controlled Trials Register is a bibliographic database of controlled trials. The Database of Abstracts of Reviews of Effectiveness (DARE) includes structured abstracts of systematic reviews which have been critically appraised by reviewers at the National Health Services Centre for Reviews and Dissemination (York, England) and by other people, e.g. from the American College of Physicians' Journal Club and the journal Evidence-Based Medicine. The Cochrane Review Methodology Database is a bibliography of articles on the science of research synthesis. The Cochrane Collaboration, a multidisciplinary international group of scholars, was developed in response to Archie Cochrane, a British epidemiologist, calling for systematic, up-to-date reviews of all relevant randomized controlled trials (RCTs) of health care in the early 1990s.
PubMed offers an online tutorial on its use. It is simple to use and covers many topics.
Principles of Searching Computerized Bibliographic Databases
- Plan your search and break your topic down into pieces. Example: patient education in ovarian cancer patients may be searched by
- 1) seeking literature about patient education,
- 2) seeking literature about ovarian cancer, and then, having the database list any articles that are in both search results. You can limit your search (e.g, by information about patients (specific gender, age, ethnicity, etc) or type of publication (clinical, research, instrument, etc).
- In each database, check the terms you use in a subject heading list. In PubMed for MEDLINE®, this is called the MeSH (Medical Subject Heading) Browser.
- Many publications found will have an abstract. Read the abstracts of several articles found in your search. Do these abstracts describe articles that may help you in answering your clinical problem? Do the research studies concern phenomenon you need to understand in your search for evidence?
- Information about one or more articles that seem pertinent to your EBP Project.
- Seek the full text version of each pertinent article and proceed to appraising the findings.
- If you go through this process several times without success, you may need to get assistance from a medical librarian.
- Questions to ask if search is not successful: Using the correct terms to search? Using the most appropriate databases or sites?
- Be aware that some topics have little published research and therefore, will lead you to an “unsuccessful” search.
When searching the internet it is important to determine the credibility of the site as well as the information. Health On the Net Foundation (HONF) has published one set of voluntary guidelines for health-related Web sites in an attempt to improve the reliability and credibility of such sites. The HONF Code of Conduct is voluntary. Web sites that meet the Code are permitted to display the HONF logo. (Basic principles regarding how to do such an assessment can be found in the following references.
- Refer to the Clark & Gomez article "Details on demand: consumers, cancer information and the Internet" for more specifics on web-based searching.
- Other excellent resources are Mehta & Jain's "Finding evidence-based answers to clinical questions online" (2001) and Kinanne & Milne’s review of how caregivers of people with cancer seek information on the internet (2010).
Continue to Step 3 - Critique