Category Archives: Evidence hierarchy

?Unexpected Evidence in The Science of Lockdowns

Headlines are blaring: “New study shows that lockdowns had minimal effect on COVID-19 mortality.”

The January 2022 systematic review and meta-analysis that underlies that news is Herby, Jonung, & Hanke’s “A Literature Review and Meta Analysis of the Effects of Lockdowns on COVID 19 Mortality” in Applied Economics .

Scientists label systematic reviews and meta-analyses as the strongest type of scientific evidence (pyramid of evidence). Of course the strength of the systematic review/meta-analysis depends on whether it is well or poorly done, so never put your research-critique brain in neutral. This one seems well done.

In systematic reviews, researchers follow a methodical, focused process that describes their selection and analysis of all studies on a topic. Meta-analyses treat all the data from those selected studies as a single study. Researchers will specify their process and parameters for selecting studies, and they typically publish a table of evidence that summarizes key information about each study. Herby et al. did so. (Note: systematic reviews should not be confused with integrative reviews in which authors are less systematic and are giving background info.)

For example, from Herby et al’s study cited above: “This study employed a systematic search and screening procedure in which 18,590 studies are identified… After three levels of screening, 34 studies ultimately qualified. Of those 34 eligible studies, 24 qualified for inclusion in the meta-analysis. They were separated into three groups: lockdown stringency index studies, shelter-in-place-order (SIPO) studies, and specific [non-pharmaceutical intervention] NPI studies. An analysis of each of these three groups support the conclusion that lockdowns have had little to no effect on COVID-19 mortality.”

See the full publication below. And rather than reading it beginning to end, first 1) read the abstract; 2) identify parameters used to select the 34 eligible studies and 24 meta-analysis studies, 3) scan the table of evidence, and 4) read the discussion beginning page 40. Then read the complete article, and cut yourself some slack—-just try understand what you can depending on your research expertise.

What do you think? Are the studies that support their conclusions strong? What are the SCIENTIFIC objections to their conclusions? What do they identify as policy implications, and do you agree or disagree?

[NOTE THAT THIS ARTICLE LINK MAY BE GOOD FOR ONLY 30 DAYS, but a librarian can help you get it after that.] Happy evidence hunting.

Evidence-based Practice Institute

I recommend this event. I have no conflict of interest.

New virtual EBP Institute – Advanced Practice Institute: Promoting Adoption of Evidence-Based Practice is going virtual this October.

This Institute is a unique advanced program designed to build skills in the most challenging steps of the evidence-based practice process and in creating an organizational infrastructure to support evidence-based health care. Participants will learn how to implement, evaluate, and sustain EBP changes in complex health care systems. 

Each participant also receives Evidence-Based Practice in Action: Comprehensive Strategies, Tools, and Tips From the University of Iowa Hospitals and Clinics. This book is an application-oriented EBP resource organized based on the latest Iowa Model and can be used with any practice change. The Institute will include tools and strategies directly from the book.

3-Day Virtual Institute

Wednesday, October 7

Wednesday, October 14

Wednesday, October 21

(participation is required for all 3 days)

Special pricing for this virtual institute: 5 participants from the same institution for the price of 4

Learn more and register for the October 2020 Advanced Practice Institute: Promoting Adoption of Evidence-Based Practice. 

Kristen Rempel

Administrative Services Specialist Nursing Research & Evidence-Based Practice

University of Iowa Health Care | Department of Nursing Services and Patient Care

200 Hawkins Dr, T155 GH, Iowa City, IA 52242 | 319-384-6737

uihc.org/nursing-research-and-evidence-based-practice-and quality

Of Mice and Cheese: Research with Non-equivalent Groups

Reposting. Enjoy the review. -Dr.H

Discovering Your Inner Scientist

Last week’s blog focused on the strongest types of evidence that you might find when trying to solve a clinical problem. These are: #1 Systematic reviews, Meta-analyses, or Evidence-based clinical practice guidelines based on systematic review of RCTs; & #2 Randomized controlled trials. (For levels of evidence from strongest to weakest, see blog “I like my coffee (and my evidence) strong!”)

So after the two strongest levels of evidence what is the next strongest? #3 level is controlled trials without randomization. (Sometimes called quasi-experimental studies.)

Here’s an example of a controlled trial without randomization: I take two groups of mice and test two types of cheese to find out which one mice like best. I do NOT randomly assign the mice to groups. The experimental group #1 loved Swiss cheese, & the control group #2 refused to eat the cheddar. I assume confidently that mice LOVE Swiss cheese…

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More? Not always better! Check out NNT.

EBPPractice based in evidence (EBP) means that you must critique/synthesize evidence and then apply it to particular setting and populations using your best judgement.  This means that you must discriminate about when (and when NOT) to apply the research.  Be sure to use best professional judgment to particularize your actions to the situation!

Add to your repertoire of EBP tools,  ratiothe Number Needed to Treat (NNT).   This is not mumbo -jumbo.   NNT explained here–short & sweet: http://www.thennt.com/thennt-explained/ 

FindingsCRITICAL THINKING:   Check out this or other analyses at the site.  How does the info on antihypertensives for mild hypertension answer the question of whether more is better?  Are there patients in whom you SHOULD treat mild HTN?  (“We report, you decide.”)   http://www.thennt.com/nnt/anti-hypertensives-for-cardiovascular-prevention-in-mild-hypertension/

MORE INFO:  Check out what the data say about other risk/benefit treatments at http://www.thennt.com/ 

Dispelling the nice or naughty myth: retrospective observational study of Santa Claus.

Naughty NiceGo to full article

Abstract

“OBJECTIVE:  To determine which factors influence whether Santa Claus will visit children in hospital on Christmas Day.

DESIGN:  Retrospective observational study.

SETTING:  Paediatric wards in England, Northern Ireland, Scotland, and Wales.

PARTICIPANTS:  186 members of staff who worked on the paediatric wards (n=186) during Christmas 2015.

MAIN OUTCOME MEASURES:  Presence or absence of Santa Claus on the paediatric ward GIFTSduring Christmas 2015. This was correlated with rates of absenteeism from primary school, conviction rates in young people (aged 10-17 years), distance from hospital to North Pole (closest city or town to the hospital in kilometres, as the reindeer flies), and contextual socioeconomic deprivation (index of multiple deprivation).

RESULTS:  Santa Claus visited most of the paediatric wards in all four countries: 89% in England, 100% in Northern Ireland, 93% in Scotland, and 92% in Wales. The odds of him not visiting, however, were significantly higher for paediatric wards in areas of higher socioeconomic deprivation in England (odds ratio 1.31 (95% confidence interval 1.04 to 1.71) in England, 1.23 (1.00 to 1.54) in the UK). In contrast, there was no correlation with school absenteeism, conviction rates, or distance to the North Pole.

CONCLUSION:  The results of this study dispel the traditional belief that Santa Claus rewards children based on how nice or naughty they have been in the previous year. Santa Claus is less likely to visit children in hospitals in the most deprived areas. Potential solutions include a review of Santa’s contract or employment of local Santas in poorly represented region.”  Park et al. (2016).BMJ. 2016 Dec 14;355:i6355. doi: 10.1136/bmj.i6355.

How would you translate this into practice?   Questions to help you with this endeavor:   Where does this retrospective, observational research fall on the evidence hierarchyEBNIs it quantitative or qualitative research?  Experimental or non-experimental research? How generalizable is this research? What are the risks,resources, and readiness of people in potentially using the findings (Stetler & Marram, 1996; Stetler, 2001)?   What might happen if you try to apply the abstract information to practice without reading the full article?  Do you think the project done in Europe is readily applicable to America?  What would be the next level of research that you might undertake to better confirm these findings?
Enjoy your holiday season! -Dr H

“Here Comes Santa Claus?” What IS the Evidence?

It’s that time of year again! Enjoy this illustration of how to use one model in applying best, available evidence to practice. Have fun and a merry and bright season.

Discovering Your Inner Scientist

How strong is the evidence regarding our holiday Santa Claus (SC) practices? And what are the opportunities on this SC topic for new descriptive, correlation, or experimental research?  Although existing evidence generally supports SC, in the end we may conclude, “the most real things in the world are those that neither children nor men can see” (Church, as cited in Newseum, n.d.).santa3

If you want to know the answers, check out: Highfield, M.E.F. (2011).  Here comes Santa Claus: What’s the evidence? Advanced Emergency Nursing Journal, 33(4), 354-6. doi: http://dx.doi.org.libproxy.csun.edu/10.1097/TME.0b013e318234ead3   Using bona fide published work, the article shows you how to evaluate the strength of evidence and how to apply it to practice.   You can request a full-text for your personal use from your library or from the author via www.researchgate.net/home .  

Critical thinking: Check out this related research study with fulltext available through PubMed: Black Pete…

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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.