Thursday, May 24, 2012

Not Always Evident - A Self-Guided Approach to Evidence

The Gist:  Evidenced based medicine (EBM) plays a critical role in emergency medicine and it's crucial to be able to interpret and apply data, especially if you don't want to practice medicine 10 years in the past.  Rather than glancing barely beyond the abstract, check out some quick tools that demonstrate key skills to help one piece together the influx of new data in a meaningful, interesting, and quick way.  Use Emergency Medicine Literature of NoteThe Skeptics Guide to Emergency Medicine (The SGEM), Twitter, and EM Nerd as the springboard - it takes minimal time and proffers great returns.  It's really not as dry or time consuming as you may think.

In medical school, we briefly covered bare bones epidemiology in preparation for board exams, but had nothing to equip us to critique articles and data.  That was fine with me until we spent two classes in one of my Master of Public Health courses on article/study analysis.  I was amazed at what the data, buried in complex inclusion criteria and analyses, actually concluded.  You can find a study to prove absolutely anything.  Perhaps many medical students glean these skills in college; however, as a Middle Eastern History major, my research was on Orientalism and gender.  I acquired an affinity for Turkish coffee, but little understanding of things like study design, confounders, absolute risk reduction, and subgroup analysis.  I'm still climbing the learning curve in this arena but seriously, if I can learn and be intrigued by this stuff, then absolutely anyone can.

Not convinced that analyzing and interpreting medical literature is important?
  • It's now tested on the USMLE Step 2 in practical application format.
  • Medicine changes constantly.  As a result, I've encountered many attendings who use students as a means of staying current.  Apply the things you learn from the literature (ex: on Family Medicine, I championed antibiotic stewardship and the new cervical cancer screening guidelines.  Saving the world, one less pap smear and one less antibiotic prescription at a time).
  • Most medical students keep the touted evidence based medicine database, UpToDate, at our fingertips.  The evidence supporting these articles is not always as robust as it seems. For example, UpToDate's overview of hyperkalemia management cites the reduction of potassium through the use of sodium polysterene resins like Kayexelate.  The actual evidence is disguised in the parenthetical reference to the journal article from 1961, sans abstract and featuring seven subjects.  Underpowered? Methodologically flawed?
FundamentalsHere's a basic tutorial.
  • What's the primary outcome measurement?  Was it met?
  • Was there a good control group?
  • Is the study sample reflective of the population? Who was left out of the study?  How was sampling conducted?
  • Are the methods clear?  Lots of loss to follow up?
  • Are there confounders?
  • Do the results apply to other people/populations?
  • Did what was measured actually mean anything to the patient?
"But this takes forever."  It can be overwhelming to think about critiquing articles, taking care of patients, cheering on our sports team, studying for boards, and pursuing a personal life.  Fortunately, there are individuals skilled in this endeavor that one can simultaneously learn from and emulate while staying current with medical literature. Note: It's neat to read the article in question before checking these opinions/interpretations and see how the analysis matches up.
  • The Skeptics Guide to Emergency Medicine (The SGEM) - A podcast aimed at encouraging evidence based practice among physicians, reducing the time from which knowledge is translated into practice.  In under 20 minutes, they review a major article/subject using the PICO format.  
  • EM Lit of Note - concise, insightful, readable synopsis of popular literature several times each week.  These critiques are easy to read and, although colored by his own opinion, provide insight into important pitfalls and clinical implications of these studies. 
  • theNNT.com assesses common treatments and diagnostic tests by the Number Needed to Treat (NNT) to prevent a bad outcome and the number of patients harmed in that same process.  Begin by checking the NNT for various standards in medical practice when you're so inclined, take a gander at the section where they describe how they calculated the numbers.  Like most things in medicine, these numbers aren't universally agreed upon, but it's a neat, helpful tool.
  • Best Bets - An evidence based medicine project that looks at the evidence behind very specific questions. 
  • SMARTEM with Dr. David Newman and Dr. Ashley Shreves.  This duo takes deep dives into the literature, from which one can absorb an incredible amount about how to deconstruct studies.  These are dense and worth more than one listen but they're well done and interesting.
  • Check out Twitter.  In this forum there's amazing international dialogue regarding medical literature.  Insightful, fiery, and humorous.  In fact, one of my favorite conversations began with the following tweet after the NEJM published a study on azithromycin and CV disease "just f***in great ."
  • Dr. Richard Lehman's Journal Review.  Dr. Lehman quickly highlights a few articles from the world's leading medical journals, providing his opinion on these studies and/or the implications that lie therein.
  • R&R in the Fast Lane can be used to briefly see what what other physicians think is important, practice changing, weird, or ridiculous in the literature

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