A Guide to Nursing - Evidence-Based Practice Research: Step Three: Appraise

Rating System for the Hierarchy of Levels of Evidence

• Level I — Evidence from a systematic review or meta-analysis of all relevant RCTs
• Level II — Evidence obtained from well-designed RCTs
• Level III — Evidence obtained from one well-designed controlled trials without Randomization
• Level IV — Evidence from well-designed case-control and cohort studies
• Level V — Evidence from systematic reviews of descriptive or qualitative study
• Level VI — Evidence from single descriptive or qualities study
• Level VII — Evidence from the opinion of authorities and/or reports of expert committees

Melnyk, B. M., & Fineout-Overholt, E. (2011). Evidence-based practice in nursing & healthcare: A guide to best practice. Lippincott Williams & Wilkins.

Finding sources is only the first part of the research process.  Once you locate sources, you need to be able to evaluate them to see if they're appropriate. 

After finding information in resources, the next step is to apply critical thinking skills and evaluate the information in relation to your health question. 

Evaluation Tools:

• Evaluate by applying the Discern Instrument which is a brief questionnaire which provides users with a valid and reliable way of assessing the quality of information for a health problem.

• A User's Guide to Finding and Evaluating Health Information on the Web (Medical Library Association) 
• Evaluating Internet Health Information (National Library of Medicine) 

• Analyze the Evidence - Penn State Department of Nursing

• Critical Appraisal Worksheets - from the Centre for Evidence-Based Medicine, interactive forms for evaluating articles on diagnosis, harm, therapy, eprognosis and systematic reviews.

• Study Designs (Centre for Evidence-Based Medicine) -A brief guide to the different study types and a comparison of the advantages and disadvantages of the different types of study.

SUNY Downstate Medical Research Library of Brooklyn

MEDLINE and the other online medical literature databases try to be as comprehensive as possible in their coverage. As a result, indexed material may have little direct application to present-day medical practice.

The different types of material indexed in MEDLINE are labeled in the pyramid diagram, with the least clinically relevant at the bottom and the most clinically relevant at the top. The four layers above case reports and case series represent actual clinical research; the layers below are least clinically relevant and can be useful as background resources.

The links below provide basic definitions and examples of clinical research designs to help the medical student or new clinician understand how the design of a research study may affect whether or not to accept its findings in caring for a patient.

More detail on each level is available by reading the pages in sequential order or by selecting from the topics below:

Use the Medical Library Association's guidelines to help you decide whether information is credible, timely, and useful.

1. Sponsorship

• Can you easily identify the site sponsor? Sponsorship is important because it helps establish the site as respected and dependable. Does the site list advisory board members or consultants? This may give you further insights on the credibility of information published on the site.
• The web address itself can provide additional information about the nature of the site and the sponsor's intent. What should you know about .com health sites? Commercial sites may represent a specific company or be sponsored by a company using the web for commercial reasons—to sell products. At the same time, many commercial websites have valuable and credible information. Many hospitals have .com in their address. The site should fully disclose the sponsor of the site, including the identities of commercial and noncommercial organizations that have contributed funding, services, or material to the site.
  • A government agency has .gov in the address.
  • An educational institution is indicated by .edu in the address.
  • A professional organization such as a scientific or research society will be identified as .org.
  • Commercial sites identified by .com will most often identify the sponsor as a company, for example Merck & Co., the pharmaceutical firm.

2. Currency

• The site should be updated frequently. Health information changes constantly as new information is learned about diseases and treatments through research and patient care. websites should reflect the most up-to-date information.
• The website should be consistently available, with the date of the latest revision clearly posted. This usually appears at the bottom of the page.

3. Factual information

• Information should be presented in a clear manner. It should be factual (not opinion) and capable of being verified from a primary information source such as the professional literature, abstracts, or links to other web pages.
• Information represented as an opinion should be clearly stated and the source should be identified as a qualified professional or organization.

4. Audience

• The website should clearly state whether the information is intended for the consumer or the health professional.
• Many health information websites have two different areas - one for consumers, one for professionals. The design of the site should make selection of one area over the other clear to the user.  

NAU Librarians are available and can assist you by chat or email. You can schedule an individual research appointment.  We will reply to emails within 24 hours, Monday through Friday (excluding holidays or other closures).   View all hours.

Currency:

• When was the information published or posted?
• Has the information been revised or updated?
• Is the information current or out-of-date for your topic?

Relevance:

• Does the information relate to your topic or answer your question?
• Have you looked at a variety of sources before determining this is the one you will use?

Authority:

• Who is the author/publisher/source?
• What are the author's qualifications to write on the topic?
• Is there contact information, such as a publisher or email address?
• What does the URL extension reveal about the author or source? (.com, .edu, .gov, .org, .net, .mli, .jobs, .biz)

Accuracy:

• Does the author cite their sources?
• Is the information supported by evidence?
• Has the information been reviewed or refereed?

Purpose:

• Do the authors/sponsors make their intention or purpose clear?
• Is the information Fact? Opinion? Propaganda?

Adapted from a handout developed by librarians at Meriam Library, California State University, Chico, 2004