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NS 4250: Nutrition Communications and Counseling

This guide provides resources and guidance for finding and evaluating nutrition information.

Evaluating Scientific Evidence

Evidence-based Medicine

Evidence based medicine is "the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients." 
Source: David Sackett, William Rosenberg, Muir Gray, Brian Haynes & Scott Richardson. Evidence based medicine: what it is and what it isn’t [internet]. BMJ; 13 January 1996 [cited 23 May 2013]. 

 

Levels of Evidence by Study Type

Level I - Evidence from a systematic review or meta-analysis of all relevant randomized controlled trials (RCTs)

Level II - Evidence obtained from well-designed RCTs

Level III - Evidence obtained from 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 and qualitative studies

Level VI - Evidence from single descriptive or qualitative studies

Level VII - Evidence from the opinion of authorities and/or reports of expert committees

Source: Melnyk BM. Implementing the Evidence-Based Practice (EBP) Competencies in Healthcare : A Practical Guide to Improving Quality, Safety, and Outcomes. ; 2016. (Table 1.1, p. 11)

 

Article Types Explained

Empirical study (or primary article):  

  • Aims to gain new knowledge on a topic through direct or indirect observation and research. 
  • Include quantitative or qualitative data and analysis.
  • In science, an empirical article will often include the following sections: Introduction, Methods, Results, and Discussion.

Review article:  

  • Provides a synthesis of existing research on a particular topic. 
  • Useful when you want to get an idea of a body of research that you are not yet familiar with. 
  • Differs from a systematic review in that it does not aim to capture ALL of the research on a particular topic.

Systematic review:  

  • A methodical and thorough literature review focused on a particular research question. 
  • Aims to identify and synthesize all of the scholarly research on a particular topic in an unbiased, reproducible way to provide evidence for practice and policy-making. 
  • May involve a meta-analysis (see below). 

Meta-analysis:  

  • A type of research study that combines or contrasts data from different independent studies in a new analysis in order to strengthen the understanding of a particular topic. 
  • There are many methods, some complex, applied to performing this type of analysis.

 

Study Design Resources and Reporting Requirements 

The CRAAP Test

Currency

  • When it comes to health, you often need current, up-to-date information. Check the website for a copyright date, or 'last updated' date, often at the very bottom of the page.
  • Try the links on the page. If many of them are 'broken', it's likely that the page has not been updated or maintained.

Relevance

  • Check that the information is relevant to your question. Choose your search terms carefully to retrieve the most relevant results.
  • Who is the intended audience of the website? Is the information meant for health consumers (lay people) or health professionals?

Authority

  • A good website will provide clear information as to the author/owner of the site and the source of the information. You should be able to find an 'About' link somewhere on the page.
  • Legitimate sites often provide contact information.
  • The web address can be a clue to authorship: .edu indicates an educational institution and .gov indicates a government website. 

Accuracy

  • The accuracy of the information can be difficult to determine, but some clues may be a warning sign. Trust your judgement and beware of sites that make health claims that you know to be false or that are debunked by another reliable, trustworthy source.
  • Beware of biased or opinionated language.
  • Steer clear of websites that are poorly written, full of grammatical errors and spelling mistakes, or lots of exclamation points.

Purpose

  • The purpose of a reliable health information website should be to teach or inform. The information should be objective and impartial.
  • Beware of sites whose primary purpose seems to be selling products, entertaining, or sites that are strongly biased or opinionated.