Without evidence of benefit, an intervention should not be presumed to be beneficial or safe.

- Rogue Medic

Common Sense vs. Evidence

 

Too Old To Work, Too Young To Retire challenges me to respond to his recent discovery of the parachute study.[1] The parachute study is from a decade ago, when Too Old was just a charming young curmudgeon.

What is common sense?

It is easier to describe what common sense is not.

What is common only appears to make sense.

What makes sense – to an individual who really understands what he is doing – is not common.

Con men rely on our belief in common sense to scam us. Maybe we should call it con man sense.

I have already written about the parachute study.[2]

The authors of the parachute study make it clear that their paper is a satire. It appears in the Christmas issue, which is the most comedic of the BMJ (British Medical Journal) issues.
 

Notes
Contributors: GCSS had the original idea. JPP tried to talk him out of it. JPP did the first literature search but GCSS lost it. GCSS drafted the manuscript but JPP deleted all the best jokes. GCSS is the guarantor, and JPP says it serves him right.
Funding: None.
Competing interests: None declared.
Ethical approval: Not required.
[3]

 

This is why actually reading the full paper, and understanding it, is important in evaluating research. When we read, and understand what we are reading, we are able to see the strengths and weaknesses of the paper.

This is why what I write about research papers tends to be much longer than what I write about everything else.

EM Literature of Note has much shorter analyses of papers. Dr. Radecki would probably respond to, and dismiss, what Too Old wrote in a short paragraph, but I am less concise.

Reading, and understanding, the whole paper is why I do not post just the abstract and some unwarranted conclusions.

That would be foolish, but that seems to be what we get from most of science reporting, including the material written by doctors for medical web sites. I am not suggesting that I am perfect. I miss stuff, too, but I will not hide it when I miss stuff.[4],[5],[6]

Perfection is the realm of the quack.

Perfection is not real, but quacks are very real and all too common.

While the parachute study points out some of the weaknesses of basing treatments on evidence (or science), nobody claims that evidence is perfect. The critics act as if evidence is supposed to be perfect, and since evidence is not perfect, then our only alternative is to fall for whatever quackery they are pushing.

Evidence is not expected to be perfect.

Evidence is still the best way we have of finding what works.
 


 

 

You can use the anecdote-based parachute provided by the ACME Alternative Parachute Company, Ltd.

There was this one time that . . . yada yada . . . twice . . . yada yada yada . . . and then he . . . I swear . . . and it totally worked!

I will use a parachute that is manufactured according to designs that have been well tested and constructed using materials that have been well tested.
 

  • We would still be using common sense and remain ignorant of the effects of H pylori in peptic ulcers if not for evidence.[7]
  •  

  • How many patients did we common sense to death when blood-letting to remove bad humors was the standard of care?[8]
  •  

  • How many patients did we common sense to death when antiarrhythmics to eliminate PVCs after a heart attack was the standard of care?[9]
  •  

  • How many patients did we common sense to death when giving high-flow oxygen for heart attacks, cardiac arrest, and everything else was the standard of care?[10],[11],[12]
  •  

  • We would still be using the common sense of internal mammary artery ligation to treat heart attacks if not for evidence.[13]
  •  

  • We would still be using the common sense of standing back and letting the medic get the line, or the tube, if not for evidence. How much did your resuscitation rate go up when you made the evidence-based change of focusing on excellent compressions?[14],[15]

 
Most of the links are to what I have written about these examples, because to list all of the research demonstrating the ways we killed people with common sense would take much more room.

You might think that common sense would include an understanding of the benefits of research, but it does not.

Maybe common sense would be more appropriately titled common ignorance.

Footnotes:

[1] Common Sense Versus Evidence Based Medicine
March 27, 2013
Too Old To Work, Too Young To Retire
Article

[2] Does the parachute study prove that research doesn’t matter? Part I
Wed, 22 Aug 2012
Rogue Medic
Article

[3] Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials.
Smith GC, Pell JP.
BMJ. 2003 Dec 20;327(7429):1459-61. Review.
PMID: 14684649 [PubMed – indexed for MEDLINE]

Free Full Text from PubMed Central.

[4] Corrections of Misleading Charts
Mon, 07 Feb 2011
Rogue Medic
Article

[5] Is the Difference in Penetrating Trauma Mortality Truly Significant? Part I
Sun, 03 Feb 2013
Rogue Medic
Article

[6] Advanced Airway vs. BVM During CPR – Which is Worse?
Sun, 10 Feb 2013
Rogue Medic
Article

[7] Timeline of peptic ulcer disease and Helicobacter pylori
Wikipedia
Article

[8] Answer to What is this Dangerous Treatment and How Long Did it Take to Stop Using it
Wed, 01 Feb 2012
Rogue Medic
Article

[9] C A S T and Narrative Fallacy
Mon, 20 Jul 2009
Rogue Medic
Article

[10] More Oxygen in the New AHA Guidelines
Tue, 26 Oct 2010
Rogue Medic
Article

[11] One hundred percent oxygen in the treatment of acute myocardial infarction and severe angina pectoris
Tue, 19 Jun 2012
Rogue Medic
Article

[12] Evidence for Oxygen in Cardiac Arrest
Wed, 10 Aug 2011
Rogue Medic
Article

[13] An evaluation of internal-mammary-artery ligation by a double-blind technic.
COBB LA, THOMAS GI, DILLARD DH, MERENDINO KA, BRUCE RA.
N Engl J Med. 1959 May 28;260(22):1115-8. No abstract available.
PMID: 13657350 [PubMed – indexed for MEDLINE]

[14] Cardiac Arrest Management is an EMT-Basic Skill
Wed, 07 Dec 2011
Rogue Medic
Article

[15] Cardiac Arrest Management is an EMT-Basic Skill – The Hands Only Evidence
Fri, 09 Dec 2011
Rogue Medic
Article

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Comments

  1. Since I played around on TOTWTYTR’s blog, being a smart-ass, I thought I could pay you the same respect!

    The beauty of the satirical parody (parodic satire?) in BMJ is that two arguments can be derived from the joke. The first is that the crown jewel of medical knowledge is the RCT. The second is that blatant common sense should be ignored.

    So perhaps we should review the high-level evidence supporting prehospital splinting of fractures. Not sure we want to sell the IRB on equipoise due to the lack of RCTs. Or how about aortic dissection – every reference describes the need to acutely lower the blood pressure dramatically, but it doesn’t appear that it has been studied in a high-quality trial. Or a lower-quality trial. Or any trial!

    I would insert a clever re-writing of the parachute study here, but dinner is ready!

    • Brooks,

      Since I played around on TOTWTYTR’s blog, being a smart-ass, I thought I could pay you the same respect!

      But I am special and deserve special treatment. 😉

      The beauty of the satirical parody (parodic satire?) in BMJ is that two arguments can be derived from the joke. The first is that the crown jewel of medical knowledge is the RCT. The second is that blatant common sense should be ignored.

      The RCT is great, when it can be done in a way that answers the question the authors think they are asking.

      Too many times, authors appear to be using common sense to justify their biases in study design. IST-3 is just one pathetically incompetent example. It certainly does not count as an RCT. It was not really randomized and it is a great example of the problems with uncontrolled studies.

      So perhaps we should review the high-level evidence supporting prehospital splinting of fractures.

      I have had one common sense advocate explain to me that the backboard is just a splint, and since there are no RCTs of splints, we do not need any to justify this obviously essential treatment.

      Fracture = splint. QED – except that I think it ends up being QUAD more often than without the backboard.

      Interventionists love doing things to patients and hate having to show any justification for their quackery.

      Ironically, TOTW is a minimalist and part of him seems to realize that a lot of what we do is wrong, but there does not appear to be the recognition that evidence is important to curb the drive to Don’t just stand there – do something!

      Not sure we want to sell the IRB on equipoise due to the lack of RCTs.

      No history of RCTs? That seems to be a description of equipoise.

      Or how about aortic dissection – every reference describes the need to acutely lower the blood pressure dramatically, but it doesn’t appear that it has been studied in a high-quality trial. Or a lower-quality trial. Or any trial!

      My prehospital treatment of aortic dissection is to get the patient to a surgeon.

      In hospital, there has been a move toward medical, rather than surgical management of aortic dissection (and many other conditions that were traditionally managed surgically).

      One of my favorite papers on this topic is –

      Spontaneous pneumothorax: time for some fresh air.
      Simpson G.
      Intern Med J. 2010 Mar;40(3):231-4. Review.
      PMID: 20446970 [PubMed – indexed for MEDLINE]

      This is an excellent, but mostly unappreciated, review of the problems with the Standard Of Care for spontaneous pneumothorax. Not that much different from the mythological treatment that persists in so many other areas of medicine.

      I would insert a clever re-writing of the parachute study here, but dinner is ready!

      Curses on your appetite! 😉

      .

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