Tag Archives: melnyk

“Is it?” “It is!” Expert opinion as valuable evidence for practice.

Remember back when you asked your mom why you should make your bed, set the table, or do some other then-distasteful task? Maybe you said, “Do I have to?”

Because I Said SoRemember her answer? Sometimes it was just: “Because I said so!” Was that enough evidence to support your practice of setting the table or making your bed?  You bet! After all she was THE expert on such things.

Likewise…is expert opinion good evidence for your practice? Yes, it is. EXPERT OPINION of individuals or committees is the 7th level of evidence for nursing practice (Melnyk & Fineout-Overholt, 2005), and should be considered.

Of course the first question that you must ask is: “Is the person/committee (who is telling you how to prevent falls, promote safety, teach patients, and so on and on) an actual EXPERT on that topic?” The answer is a matter of judgment. If the person/committee has special education, credentials, or experience or is a recognized authority on the topic about which they are giving advice, then you could reasonably conclude yes, they are experts. In that case the advice should be considered evidence for practice.    (Caution: Your judgment of their expertise matters!–don’t just follow along.  Don’t forget that person who is expert in one area may not be an expert in another.)

The 2nd question that you must ask is; “Does any research or stronger level of evidence exist on the topic?”

  • If it does NOT exist, then you should use that expert opinion in combination with scientific principles, anecdotal case reports, and theory. Or you might create some new research yourself. (Source=Iowa EBP Model)
  • If it DOES EXIST, then you should pay most attention to the stronger evidence and interpret the weaker evidence of expert opinion in that light.

QUESTIONCritical thinking:  Try your new knowledge in this example. Many educators and professionals who run journal clubs consider journal clubs effective based on feedback from participants. At least in 2008, 80% of experimental studies suggested that journal clubs helped with learning and being able to critically review a research article. However, no research is available on whether the learning from journal clubs actually translates into practice (Deenadayalan et al., 2008). You are considering a journal club. What would you decide to do and why?

For more, see:


“I like my coffee (and my evidence) strong!”

Let’s say you are still working to solve the issue of whether gum chewing reduces post-operative ileus. You identified titles of all relevant articles using PubMed database (http://www.ncbi.nlm.nih.gov/pubmed), and had the librarian pull the full articles for you.

Now you find yourself looking at a formidable stack of articles on the topic. You are sure that some are probably better quality than coffee2others, but how can you tell?

Professionals have agreed on which types of evidence are strongest. Here’s one well-accepted hierarchy form strongest #1 to weakest #6 (Melnyk & Fineout-Overholt, 2005).

  1. Systematic reviews, Meta-analyses, or Evidence-based clinical practice guidelines based on systematic review of RCTs
  2. Randomized controlled trial
  3. Controlled trials without randomization
  4. Case controlled or cohort studies
  5. Systematic review of descriptive studies
  6. Single descriptive or qualitative study
  7. Expert opinion of individuals or committees

Number 1= Strongest.   Number 6=Weakest

When you are trying to solve a problem, FIRST look for the three (3) types of evidence that are the very strongest (#1). These are:

  1. Systematic reviews that are summaries of research findings from many studies;
  2. Meta-analyses that are summaries of research findings in which the data from those other studies are combined into one big study;
  3. Evidence-based clinical practice guidelines that are clinical recommendations based on a summary of research and other evidence. An expert panel has often agreed on the summary and recommendations.

Your next strongest option, #2, is at least one randomized controlled trial (RCT). In an RCT a group of subjects is randomly separated into at least two groups. One group gets the experimental treatment—whether it is a drug or teaching plan or something else—and the other group usually gets standard treatment or a placebo. Then the group outcomes are compared statistically to see which did better.

Usually the title or first few lines of the article will tell you that the article is a systematic review, a meta-analysis, an evidence-based clinical practice guideline, or an RCT. Rarely is this left a mystery! (Never assume that a research study article is strong just because you LIKE the findings, or that it is weak because you DON’T like the findings.)

I’ll comment on other levels of evidence soon, but let’s focus on the strongest types first. Try the critical thinking for practicing the ideas above.

Critical Thinking:  Using the article titles below, rank these three (3) research studies in order from Strongest evidence to Weakest evidence:

Want to read more?  A good summary of one hierarchy is and why it’s important is at this 5 minute youtube video: https://www.youtube.com/watch?v=5H8w68sr0u8 . While that hierarchy does not precisely match the one above, the video still has lots of good information.