Date: February 18th, 2019

Guest Skeptic: Dr. Shahriar Zehtabchi is a tenured professor and Vice Chair of Academic Affairs in the Department of Emergency Medicine at SUNY Downstate Medical Center & Kings County Hospital. He has been teaching evidence-base medicine for many years and currently is the editor-in-chief of the EBM website TheNNT.com. Shahriar also serves as an editorial board member and associate editor for Academic Emergency Medicine journal.

Shahriar and I discussed the following:

* The NNT and NNH as a concept

* How to use the NNT/NNH to communicate with patients

* Weaknesses of the NNT

* What topics are covered on TheNNT.com and how they are selected

* Their peer review process for quality control

* Whether or not they have a policy to identify conflicts of interest

* Dr. Zehtabachie’s role as editor-in-chief

Guest Skeptic: Dr. Eddy Lang is a Professor and Department Head for Emergency Medicine Cumming School of Medicine, University of Calgary, Scientific Director Emergency Strategic Clinical Network and BEEM faculty member.

TheNNT.com updated their website January 11th, 2019 changing the recommendation of tPA for acute stroke from RED (no benefit) to GREEN (benefit > harms). Eddy was the lead author of the new recommendation and when it was posted it got the twitterverse very excited.

I reached out to Dr. Hoffman to discuss this change.  Then Eddy was invited to come on the SGEM to discuss why the change was made.

Eddy and I talked about the following:

* My stated position on thrombolysis for acute CVA

* His impression of the twitter storm

* His stated position on thrombosis for acute CVA and synopsis of the evidence

* Why he picked Dire Straights the Walk of Life as the theme music

* The claim that the modified Rankin Scale (mRS) is reliable and validated

* Limitations/weaknesses of the IST-3 Trial

* GRADE Methodology

* Inclusion and exclusion of different thrombolytic molecules in SRMAs

* Various guidelines

* Emberson et al SRMA from the Lancet

* Why they changed the recommendation from RED to GREEN

* The claim that time is brain

* ~1/3 of stroke are determined to be mimics

* Thrombolysing patients without strokes (mimics)

* Need for replication of trials in medicine

* The ethics of replicating the NINDS trial

* What Eddy says to patients/family at the bedside

* The impact of conflicts of interest in the production and interpretation of the literature

Each of us will have different levels of evidence that will convince us to change our practice. I respect that two people can look at the same literature and come to a different conclusion. The burden of proof is on those making the positive claim that tPA results in a net patient-oriented benefit in acute ischemic stroke. In my opinion, the burden of proof has not been met and I remain skeptical. I am happy to change my mind if presented with stronger evidence.

Remember to be skeptical of anything you learn, even if you heard it on the Skeptics’ Guide to Emergency Medicine.

Additional Resources:

* SketchyEBM – Knowing NNT

* Chiong et al. Testing the Presumption of Consent to Emergency Treatment for Acute Ischemic Stroke. JAMA 2014

* Banks and Marotta. Outcomes Validity and Reliability of the Modified Rankin Scale: Implications for Stroke Clinical Trials. A Literature Review and Synthesis.