Tag Archives: Evidence hierarchy

“How many articles are enough?” Is that even the right question?

How do you know when you have found enough research evidence on a topic to be able to use the findings in clinical practice? How many articles are enough? 5? 50? 100? 1000? Good question!

You have probably heard general rules like these for finding enough applicable evidence: Stick close to your key search terms derived from PICOT statement of problem; Use only research published in the last 5-7 years unless it is a “classic; & Find randomized controlled trials (RCTs), meta-analyses, & systematic reviews of RCTs that document cause-and-effect relationships. These are good strategies. The only problem is that sometimes they don’t work!

Unfortunately, some clinical issues are “orphan topics.” No one has adequately researched them. And while there may be a few, well-done, valuable published studies on the topic, those studies may simply describe bits of the phenomena or focus on how to measure the phenomena (i.e., instrument development). They may give us little to no information on correlation and causation. There may be no RCTs. This situation may tempt us just to discard our clinical issue and to wait for more research (or of course to do research, but that could take years).

In her classic 1998 1-page article, “When is enough, enough?” Dr. Carol Deets, argues that asking how many research reports we need may be the wrong question! Instead, she proposes, we should ask, “What should be done to evaluate the implementation of research findings in the clinical setting?”

When research evidence is minimal, then careful process and outcome evaluation of its use in clinical practice can: 1) Keep patient safety as the top priority, 2) Document cost-effectiveness and efficacy of new interventions, and 3) Facilitate swift, ethical use of findings that contributes to nursing knowledge. At the same time, Deets recognizes that for many this idea may be revolutionary, requiring us to change the way we think.

So back to the original question…How many articles are enough? Deets’ answer? “One study is enough” if we build in strong evaluation as we translate it into practice.

Reference: Deets, C. (1998). When is enough, enough? Journal of Professional Nursing, 14(4), 196. doi.org/10.1016/S8755-7223(98)80058-6

Missing in Action: The Pyramid foundation

Last post I commented on the potentially misleading terms of Filtered & Unfiltered Filtered Unfiltered jpgresearch.  My key point?  Much so-called “unfiltered research” has been screened (filtered) carefully through peer-review before publication; while some “filtered research”  may have been ‘filtered’ only by a single expert & be out of date. If we use the terms filtered and unfiltered we should not be naive about their meanings. (Pyramid source:  Wikimedia Commons )

This week, I address what I see as a 2nd problem with this evidence based medicine pyramid.  That is, missing in action from it are descriptive, correlation, & in-depth qualitative research are not mentioned.  Where are they?  This undercuts the EBM pyramid as a teaching tool and also (intentionally or not) denigrates the necessary basic type of research on which stronger levels of evidence are built.  That foundation of the pyramid, called loosely “background information,” includes such basic, essential research.

Ask an ExpertYou may have heard of Benner’s Novice to Expert  theory.  Benner used in-depth, qualitative interview descriptions as data to generate her theory.  Yet that type of research evidence is missing from medicine’s pyramid!  Without a clear foundation the pyramid will just topple over.  Better be clear!

I recommend substituting (or at least adding to your repertoire) an Evidence Based NURSING (EBN) pyramid.  Several versions exist & one is below that includes some of the previously missing research!  This one includes EBP & QI projects, too! Notice the explicit addition of detail to the below pyramid as described at https://www.youtube.com/watch?v=MfRbuzzKjcM.EBN

Critical thinking:  #1List some EBM & EBN pyramid differences.  #2 Figure out where on the hierarchy this project would go: Crowell, J., OʼNeil, K., & Drager, L. (2017). Project HANDS: A bundled approach to increase short peripheral catheter dwell time. Journal of Infusion Nursing, 40(5), 274-280. doi: 10.1097/NAN.0000000000000237.   1st use medicine’s EBM pyramid; & then 2nd use nursing’s EBN pyramid.  #3 Label Crowell et al.’s study as filtered or unfiltered and explain what you mean by that.

For more info:  Watch the YouTube video at the link above.