Ben is more correct than he allows: not only are dramatic effects rare in medicine, but large (absolute) effects are rare too. How many treatments can people in this forum name with a larger than 20% absolute risk reduction that has been discovered in the last 25 years?
From: <Djulbegovic>, "[log in to unmask]" <[log in to unmask]>
Reply-To: "[log in to unmask]" <[log in to unmask]>
Date: Friday, 27 November 2015 00:29
To: "[log in to unmask]" <[log in to unmask]>
Subject: Re: systematic review of ... parachute use to prevent death and major trauma related to gravitational challenge
Indeed, the parachute example is a very important concept in EBM- it says that when the effects of health intervention are very large ("dramatic effects") they override the combined effects of bias and random errors. When the large effects are detected we do not need RCTs to evaluate health interventions effects. The problem is that the large effects similar to parachutes do not exist in medicine (I am not sure but I would think that without parachute 1 in 1,000 people may survive plane fall, while with the parachute that ratio is probably 99 to 1). However, what exactly constitute dramatic effects is empirically unresolved question in medicine.Ben DjulbegovicUSF
Sent from my iPhone(Please excuse typos & brevity)...whatever the result of the suggested appraisal (unnecessary I think, but just a personal opinion), the message of the paper was crystal clear, one of the clearest given the circumstances of EBM at the time. Hint: it had nothing to do with skydiving ...
Juan M. Acuńa, M.D., MSc, FACOGChair, Department of Medical and Population Health Sciences ResearchHerbert Wertheim College of MedicineFlorida International University
11200 SW 8th St.AHC1-445Miami, FL 33199
Phone: 305 348 0676Email: [log in to unmask]
Thank you Carol, will it make an excuse not to appraise it for methodologic rigor, assumptions, strategy, and internal validity , i.e what BMJ stands for?
and finally, what about grey literature (departments of defence world-wide- the main customers and commissioners of this interventions)..
Nick Myles,
former skydiver
From: Carol Lefebvre [mailto:[log in to unmask]]
Sent: Thursday, November 26, 2015 1:25 PM
To: Myles, Nickolas [PH]; [log in to unmask]
Cc: Carol Lefebvre
Subject: RE: systematic review of ... parachute use to prevent death and major trauma related to gravitational challenge
Just to be clear, this was from the Christmas issue of the BMJ.
For those unfamiliar with what that means, try searching “bmj christmas articles” in Google or similar.
All the best
Carol
Carol Lefebvre
Independent Information Consultant, Lefebvre Associates Ltd, Oxford, UK
Co-Convenor, Cochrane Information Retrieval Methods Group
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From: Evidence based health (EBH) [mailto:[log in to unmask]] On Behalf Of Myles, Nickolas [PH]
Sent: 26 November 2015 21:09
To: [log in to unmask]
Subject: Re: systematic review of
I am wondering if someone can come with the critical appraisal of this systematic review, please (no time wasted is guaranteed):
Parachute use to prevent death and major trauma related
to gravitational challenge: systematic review of
randomised controlled trials
Gordon C S Smith, Jill P Pell
BMJ 2003;327:1459–61
Cheers,
NM
Nickolas Myles, MD, PhD, MSc, FRCPC
Anatomical pathologist, St.Paul’s Hospital,
Clinical Associate Professor, University of British Columbia
Department of Pathology and Laboratory Medicine
1081 Burrard St, Vancouver, BC, V6Z1Y6
Phone (604) 682-2344 x 66038
Email: [log in to unmask]
From: Evidence based health (EBH) [mailto:[log in to unmask]] On Behalf Of Burls, Amanda
Sent: Thursday, November 26, 2015 8:29 AM
To: [log in to unmask]
Subject: Open invitation to a great talk by Janet Martin
I recently attended the excellent Evidence-Based Health Care Teachers and Developers Conference in Sicily where an superb talk was given by Dr Janet Martin about her, as yet unpublished, research into the validity of research evidence. Janet is the Director of MEDICI (Medical Evidence, Decision Integrity, Clinical Impact) and Co-Director of the High Impact Technology Evaluation Centre (HiTEC) in London, Canada.
Her talk was so relevant and interesting I invited her to speak at the School of Health Science at City University London.
Her talk on "What proportion of the published medical literature is valid and relevant?" Will take place from 11 to 12 am on Thursday 10th December In Room MG26 School of Health Sciences, Myddelton Street, London, London EC1V 0HB
Best wishes
Amanda
Amanda Burls
Professor of Public Health
Health Services Research and Management Division
School of Health Sciences
Myddleton Street
City University London
London EC1V 0HB
T: +44 (0) 207 040 5409
M: +44 (0) 7970 271 743 (Internal code 1274)
Twitter ID: ajburls
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