Rapid Responses to:
|
|
Rapid Responses: Rapid Responses published:
-
![[Read Rapid Response]](/icons/misc/sectionDOWN.gif)
Uh huh
- Joseph E Morales (19 December 2003)
-
Parachutes, padded pants and beneficence
- Peter Griffiths (19 December 2003)
-
inherently dangerous behaviors
- Emily Jane Woo, MD, MPH (19 December 2003)
-
Parachute trials
- Allen J Parmet, MD (19 December 2003)
-
Excellent Article for Citation and Debate
- Stephen J Véronneau MD (19 December 2003)
-
Isn’t that unethical?
- Carlos Cuello (20 December 2003)
-
Dr
- Zachary T Bloomgarden (20 December 2003)
-
Qualitative Data Collection?
- Ashley P Simons-Rudolph (20 December 2003)
-
alternative parachutes
- David Brookman (20 December 2003)
-
Social costs need to be considered
- Mike Thomas (20 December 2003)
-
Social costs need to be considered
- Mike Thomas (20 December 2003)
-
Evidence and practice
- Martin J Dumskyj (22 December 2003)
-
Publication bias may explain the (lack of) review's findings
- Victor M. Montori (23 December 2003)
-
Anecdotal support for short course of parachute therapy
- Robert N C Pfeifer (24 December 2003)
-
Blinding and class effect?
- Barry J Lyons (29 December 2003)
-
What is EBM
- Aviel Roy-Shapira (31 December 2003)
-
Evidence-based medicine (EBM) or prejudiced based medicine (PBM)?
- Sean Lynch, EX2 5AF (31 December 2003)
-
Do straw men need parachutes?
- Lee A. Green (1 January 2004)
-
On the Value of Evidence for Parachutes
- Scott D Ramsey (21 January 2004)
-
Secondary Gain
- Terence Silverton (23 January 2004)
-
On the other hand....Type I travails
- Jack E. Rosenblatt, M.D. (26 January 2004)
-
Poppycock and rubbish
- Richard A. Davidson, MD,MPH (27 January 2004)
-
RCTs
- Colin G Gibson (28 January 2004)
-
Evidence-based medicine is not THAT funny
- Robert J. Temple, M.D. (30 January 2004)
-
Dedication and rhetoric through chemical imbalance and sleep deprivation
- Jason D. Carroll (2 February 2004)
-
Parachutes and medical interventions: An unfair comparison
- Rajiv Sarin (4 February 2004)
-
Evidence-base for using insulin to treat diabetics: can it ever be complete?.
- Richard G Fiddian-Green (5 February 2004)
-
EBM: A Postmodern Phenomenon
- Grace E. Jackson, MD (22 February 2004)
-
Noah's Parachute?
- Paul R. Chelminski (11 March 2004)
-
Evidence Base for EBM ?
- Howard McNulty (11 May 2004)
-
Flaw in analysis
- John Tukey (7 August 2004)
-
Parachutes and male circumcision: any similarity?
- Julius Atashili (15 October 2004)
-
Re: Evidence-based medicine is not THAT funny
- Larry M. Weisenthal (24 November 2005)
-
Hang Glider Pilot Response
- C Williams (19 September 2006)
-
Time to Ponder Over What We Consider Evidence
- GS Umamaheswara Rao (4 October 2006)
-
Non-medical response
- Peter A Dulimov (12 January 2007)
-
Re: Non-medical response
- Sharon R Bridgeman (21 February 2007)
-
Fun, but perhaps not so much
- Timothy R. Church (3 May 2007)
-
Comment on: Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials
- Nibu .A . George (8 December 2007)
-
Therapy, regulation, insurance
- Phil Goetz (26 August 2008)
|
|
|||
|
Joseph E Morales, Occupational Medicine Sacramento CA
Send response to journal:
|
You are da man! Competing interests: None declared |
|||
|
|
|||
|
Peter Griffiths, Senior Lecturer King's College London, SE1 8WA
Send response to journal:
|
I am loath to accuse a colleague of deliberate bias but I fear that Smith and Pell's review of parachute use may simply be an attempt to pour ridicule on evidence based health care. They have biased their inclusion criteria to examine all gravitational challenges, thus allowing them to offer examples of falls without parachute where impact was not fatal. Thus they argue trials are required. The review fails to fully consider landing surface and angle of impact and I am confident that if proper parameters had been determined - say fall of more than 3000m onto a resistant surface at with an angle of approach of between 80 and 100 degrees - the observational evidence for the use of parachutes would become compelling and their review exposed as the ideologically biased work it surely is. To the best of my knowledge such a fall has never been survived whereas parachutists survive such gravitational challenges every day. However, we all know that a simple trip and a fall to the ground are rarely fatal. It might be perfectly reasonable to conduct a trial to determine the effectiveness of parachutes in such circumstances. I for one would demand powerful evidence before being convinced of the need to wear a preventative parachute while going about my day-to-day business. It is issues such as this, where benefits are less obvious, that the complexities of evidence based medicine are best designed to clarify. In passing I note (with sadness) that even when evidence of protective interventions for less severe gravitational challenge is already encouraging, as in the case of 'hip protectors’ (which my colleagues and I prefer to refer to as padded pants)(1) it is hard to persuade people to use them. Clearly should any evidence for the effectiveness of parachutes in less severe gravitational challenge be forthcoming it will need to be backed by legislation compelling their use. Perhaps the medical profession should already be campaigning to make the insertion of padding into all undergarments sold in the UK compulsory? The model for this can be the campaign for mass fluoridisation of water (supported by the BMA) where less than compelling observational evidence is being used to impose medication on the population. No doubt all opponents of evidence based practice will join me in applauding this advance. Smith and Pell can be reassured that evidence based healthcare is by no means pervasive. Or could it be that we share a common belief that everything has its limits (including evidence based practice, the unchallenged beneficence of health care professions as well as the benefits or otherwise of parachutes, padded pants and fluoride)? The precise location of the boundaries are legitimately subject to discussion where opinions values and ethics rightly dominate. By the way, I will happily volunteer to participate in a trial of parachutes for falls onto a soft mattress from distances in the range of 10-100 cm. 1. NHS Centre for Reviews and Dissemination. Preventing Falls and Subsequent Injury in Elderly People. Effective Health Care 1996;2(4). 2. NHS Centre for Reviews and Dissemination. Systematic review of the efficacy and safety of the fluoridation of drinking water. York: University of York; 2000. Competing interests: I teach a course which suggests to students that utilising evidence in their practice might not be an entirely bad thing. I get paid to do this. |
|||
|
|
|||
|
Emily Jane Woo, MD, MPH, Medical Officer US Food and Drug Administration, 1401 Rockville Pike, Rockville, MD 20852 USA
Send response to journal:
|
This is great! On a serious note, I think that people need to consider mobile phone use by drivers. The legislators in my state say that there's no proof that driving with a cell phone (hand-held or not) increases the risk of collision and injury. (This is the same state which only recently started treating fatal drunk driving and fatal hit-and-run as serious crimes.) I keep arguing that there have been no studies to see whether shooting people in the chest causes any permanent harm (an act which--like falling from 10,000 meters--is not uniformly fatal), yet such behavior is illegal. Some activities are so intrinsically dangerous that the potential harm is self-evident. Competing interests: None declared |
|||
|
|
|||
|
Allen J Parmet, MD, University of Kansas School of Medicine Kansas City, MO 64108
Send response to journal:
|
Historically many parachute trials were conducted during 1914-18. The great powers of Europe (Great Britain, France, Austro-Hungary, Russia, Ottoman Empire, Italy) along with minor contributors (USA, Japan, Serbia, Rumania, Luxemburg, Belgium, Greece, Bulgaria, Portugal and many colonial draftees) conducted a series of human use protocols which involved significant morbidity and mortality. Amongst these were several that used forces of gravity as a variable. In particular, those individuals who operated observation balloons filled with hydrogen were at considerable risk of injury from heat and gravitational acceleration. A large majority were equipped with and utilized a device called a parachute which had a significant protective effect (P>0.0001). Due to the fact that the British authorities felt that the use of any such devices would lead the occupants to recklessly abandon their valuable government-issued equipment just because of the impending threat of death from fire, explosion or impact, the authors were probably not aware of these studies done by other competing governments. Competing interests: Aviation Medical Examiner (USA) |
|||
|
|
|||
|
Stephen J Véronneau MD, Research Medical Officer Civil Aerospace Medical Institute 73169
Send response to journal:
|
Well done, an article to bring a smile to the reader. I have often proposed a similar randomized controlled trial with respect to other such obvious phenomenon as oxygen requirements in humans. The art and science of medicine, the actual practice of medicine, necessitates a balance be established between those requiring a research study of everything before acting and those who would prefer extreme latitude in clinical decision making. The SARS epidemic last year as an example of why we cannot always wait for evidence-based-guidelines, and inappropriate antibiotic prescribing an example of the latter decision making style. The parachute and oxygen reseach highlight that when the outcome is so large and the difference so clear between groups, the less the need for evidence-based-medicine. That said, the smaller the clinical effect that might be seen in any treatment, the greater the need for careful study design and analysis. The greater and more complex the data, such as DNA microarray experiments, the greater the need for controls, randomization and careful consideration of vast and complex sets of data. Simple observation will not suffice in that situation. As a proponent of evidence-based-medicine, I welcome the parachute based reality test confrontation of absolutism. I did check to make sure the article was not posted 1 April, as thus decided to reply. Competing interests: None declared |
|||
|
|
|||
|
Carlos Cuello, ITESM Av. Morones Prieto 3000 pte 64710 Monterrey, Mexico
Send response to journal:
|
I congratulate the author for his extensive research and for giving us some notion about the lack of evidence on this particular topic. When I took my first evidence-based medicine course I felt a little disappointed about the lack of evidence in many areas. I also learned that there is a wide spectrum and "grey zones". The first article that I looked for in PUBMED was a randomized controlled trial about the use of epinephrine in cardiac arrest. Obviously I didn’t find anything (at least not in humans). Likewise I didn’t find anything about furosemide in acute pulmonary edema… Well, it seemed likely that there are obvious situations where the evidence-based medicine is not necessary. But before the last decade, it would be considered unwise and unethical to put the babies on their backs to sleep just to see if the sudden infant death rate increases or decreases. I can mention an anecdote of the skydiving student Sharon McClelland, 26, who had just amazingly survived a 10,000-foot plunge in September 1994 near Queensville, Ontario, into a marsh when her parachute malfunctioned, but, as an skeptic, I would only consider this a very weak evidence… Competing interests: None declared |
|||
|
|
|||
|
Zachary T Bloomgarden, endocrinologist NY, NY USA 10028
Send response to journal:
|
OK, I understand that this is a spoof - But should one therefore believe that all other articles in this issue of the BMJ (in particular the one recommending silver-colored car use and the seemingly very thoughtful article discussing stories vs evidence) are also spoofs? Competing interests: I write articles myself although usually keeping them "straight." |
|||
|
|
|||
|
Ashley P Simons-Rudolph, doctoral student The George Washington University
Send response to journal:
|
Where's the qualitative data in all of this? With the small sample size and propensity to answer honestly just before impending death, the question seems to beg a qualitative methodology....maybe not an in-depth interview though :) Competing interests: None declared |
|||
|
|
|||
|
David Brookman, senior lecturer Newcastle, Australia, 2308
Send response to journal:
|
The authors have neglected the RAF records of the first world war in which parachutes were considered a cowards way out and would lead to abandonment of his majesty's flying craft. At least a time series is better than nothing. Our altmed colleagues will no doubt cite the cases where people have fallen from aircraft and fallen on snowy sloped roofs and hay stacks and survived as proof of the existance of suitable alternatives to the nasty medicalisation of falls from aircraft. Such people of course prefer the fantasy of the Satanic Verses (Rushdie) to the reality of being scraped from the tarmac like a lump of strawberry jam (as so wonderfully expressed in one of my recalls from childhood). Competing interests: None declared |
|||
|
|
|||
|
Mike Thomas, GP Gloucestershire Minchinhampton, Stroud, Gloucs GL6 9JF
Send response to journal:
|
Editor Smith et al (1) are right to highlight the inadequate evidence-base to the use of parachutes, but their calls for the greater use of the ill-defined and unquantifiable property ‘common-sense’ in research is unscientific and needs to be challenged. Have the authors considered the social and economic consequences of their recommendations? Are they unaware of the comfortable and profitable industry that has arisen around ‘evidence- based’ systematic reviews of controlled trials? The measures they suggest may lead to widespread economic and intellectual redundancy, and force large numbers of academics to leave behind old certainties and start thinking for themselves. This could have dangerous consequences such as forcing original thought and research, and these need careful monitoring. 1. Smith G, Pell JP. Parachute use to prevent death and major trauma related to gravitational challenge: a systematic review of randomised trials. BMJ 2003:327;1459-61 Competing interests: None declared |
|||
|
|
|||
|
Mike Thomas, GP Gloucestershire Minchinhampton, Stroud, Gloucs GL6 9JF
Send response to journal:
|
Editor Smith et al (1) are right to highlight the inadequate evidence-base to the use of parachutes, but their calls for the greater use of the ill-defined and unquantifiable property ‘common-sense’ in research is unscientific and needs to be challenged. Have the authors considered the social and economic consequences of their recommendations? Are they unaware of the comfortable and profitable industry that has arisen around ‘evidence- based’ systematic reviews of controlled trials? The measures they suggest may lead to widespread economic and intellectual redundancy, and force large numbers of academics to leave behind old certainties and start thinking for themselves. This could have dangerous consequences such as forcing original thought and research, and these need careful monitoring. 1. Smith G, Pell JP. Parachute use to prevent death and major trauma related to gravitational challenge: a systematic review of randomised trials. BMJ 2003:327;1459-61 Competing interests: None declared |
|||
|
|
|||
|
Martin J Dumskyj, Consultant in Diabetes and Endocrinology Royal Free Hospital, London, NW3 2QG
Send response to journal:
|
I would like to thank Smith and Pell for their splendid systematic review of parachute use (1). I wonder if I might drop into the discussion with the following anecdote: During my time as a registrar in general medicine a zealous young house physician was berating myself and our consultant for being sceptical about the dogmatic application of so called evidence based medicine. The conversation moved on to a recent case of meningococcal meningitis with associated septicaemia, and our senior house officer was congratulated for a rapid diagnosis and prompt action, including the prompt administration of appropriate intravenous antibiotics. It occurred to us that the use of antibiotics in the treatment of meningoccocal infection had never been subjected to a randomised controlled trial. The house officer declined to submit to deliberate infection followed by randomized treatment or placebo, and developed a new respect for observational evidence, expert opinion and the experience of his senior colleagues. 1.Smith G, Pell JP. Parachute use to prevent death and major trauma related to gravitational challenge: a systematic review of randomised trials. BMJ 2003:327;1459-61 Competing interests: I am a tax payer and therefore have a huge financial interest in the NHS. If ever a patient I would like to be treated wisely, not according to dogma. |
|||
|
|
|||
|
Victor M. Montori, Assistant Professor of Medicine Mayo Clinic College of Medicine
Send response to journal:
|
Two friends of mine, zealots of EBM as they were, decided to conduct the trial that Smith and Pell suggest, except that they disregarded the crossover design as the outcomes of falling from high altitudes are often not reversible. Their trial (n=2) was conducted with adequate allocation concealment and blinding; the analysis was by intention-to-treat and there were no losses to follow-up. There was no funding for this study. The trial was exempt from research ethics review since the investigators were going to conduct the study on themselves without enrolling volunteers. They both left signed informed consents. One of the research assistants (I) tossed a coin privately and told the guy fixing the parachutes to put a functional parachute in one backpack and another identically-looking-and-feeling mass of fabric and ropes in the other backpack. The backpacks had the names of the investigators in them, but these names were concealed from me and from the guy fixing the parachutes. The investigators-research subjects remained unaware of the allocation at the time of jumping off the plane, as their smiling faces indicated. Then, they jumped; the one with the parachute survived, the other guy died on impact (I, the outcome assessor was no longer blind to allocation). The survivor was psychologically devastated (felt worse than being dead) and killed himself 3 months later. While there may well be some threats to applicability and the estimate is imprecise given the small sample size, this trial was superbly conducted and the 100% reduction in the risk of dying on impact is clearly valid and convincing. However, at 3 months there was no difference in mortality between the study arms; quality of life seemed worse for the subject in the parachute arm of the study. This study remained, until now, unpublished given that both investigators died during its conduct. Those who, like me, participated as research assistants in this study, wanted to write this up and submit it for publication, but were convinced that it would not get published because it was a negative study. Unfortunately, Smith and Pell did not contact us or we would have provided them with our unpublished data. As this is not a Cochrane review, Smith and Pell may not update their review to include the study of my defunct colleagues. In summary, given the posthumous data from this trial, the consistent evidence from observational studies, and the clearly understood biology, people jumping from airborne planes and who place greater value in surviving the fall than on the inconvenience of carrying a parachute and the suffering of a longer fall should use a parachute and deploy it after jumping. Further research is needed to determine whether different kinds of parachutes, sky-diving expertise, timing (in meters from the ground) of parachute opening, or the metabolic syndrome affect outcomes. Competing interests: I enthusiastically promote evidence-based clinical practice. Further, I endorse the principle that states that you have to be uncertain as to the answer to the research question before conducting a randomized clinical trial. |
|||
|
|
|||
|
Robert N C Pfeifer, Locum SHO in A&E Royal Shrewsbruy Hospital SY3 8XQ
Send response to journal:
|
I note the authors' concern that use of parachutes has not been clinically validated in randomised controlled trials, in particular their concern about unnecessary medicalisation of gravitational challenge. Although observational data currently favour parachute intervention for severe challenges, optimal duration of therapy has yet to be determined. It is largely accepted that treatment is only required in the acute event, but is ongoing application of treatment to every acute event warranted? Anecdotal evidence[1] suggests that early parachute usage may lead to increased ability to manipulate trajectory and rate of fall by means of body posture. However, due to our current culture of parachute dependence I am unaware of any comparisons to date of morbidity or mortality in non-intervention free fall between experienced and inexperienced free fallers. It may be that parachutes are only required for the first few presentations of acute gravitational challenge. However, first it will be necessary to develop a suitable protocol for parachute withdrawal for the dependent. A possible subject for a medical student research project perhaps? [1] Pfeifer RNC, overheard at parachutists' bar, Langar Airfield, 1998 Competing interests: Previous committee member of Nottingham University Parachuting Club |
|||
|
|
|||
|
Barry J Lyons, Pharmacist Nipawin Hospital, Nipawin Sk CANADA
Send response to journal:
|
Did the authors consider that the lack of comparative trials may be due to the ethical concerns involved in blinding study participants, either literally or figuratively, in both the control and intervention group? The authors also apparently found no comparisons between the different ‘chutes’ used in the prevention of death or trauma in gravitational challenge. Using the assumption that using a chute is safer than no intervention at all, can we also assume that this is a class effect? Are any companies promoting a “super-chute?” Perhaps this is a situation where it is best to chute first and ask questions later. Competing interests: I own no shares in any company that produces parachutes |
|||
|
|
|||
|
Aviel Roy-Shapira, Senior Staff Surgeon Soroka University Medical Center, Beer Sheva, Israel 84101
Send response to journal:
|
Smith and Pell succeeded in amusing me, but I think their spoof reflects a common misconception about evidence based medicine. All too many practitioners equate EBM with randomized controlled trials, and metaanalyses. EBM is about what is accepted as evidence, not about how the evidence is obtained. For example, an RCT which shows that a given drug lowers blood pressure in patients with mild hypertension, however well designed and executed, is not acceptable as a basis for treatment decisions. One has to show that the drug actually lowers the incidence of strokes and heart attacks. RCT's are needed only when the outcome is not obvious. If most people who fall from airplanes without a parachute die, this is good enough. There is plenty of evidence for that. Going back to the hypertension example, I don't need an RCT to show that very high blood pressures should be treated. The patients will have symptoms, and the risk of a major catastrophe is imminent. In contrast, I must have an RCT for mild hypertension, since the outcome of non-treatment vs treatment with any given drug is not altogether clear. EBM is about using outcome data for making therapeutic decisions. That data can come from RCTs but also from observation Competing interests: None declared |
|||
|
|
|||
|
Sean Lynch, Honorary Senior Clinical Research Fellow Mental Health Research Group, Peninsula Medical School, Wonford House Hospital, Dryden Road, Exeter, EX2 5AF
Send response to journal:
|
I was interested in the comments on EBM by Roy-Shapira (31/12/03 e- BMJ). I feel that some cogent points have been made about EBM as a tool for improving clinical practice. This reflects the tensions between a knowledge-based hypothetico-deductive and "inductive" approach in medicine. However, I feel that the "Achilles Heel" of some current uses of EBM is the selection of the evidence and whether certain data or studies constitute evidence. Therein lies the risk to the return to the days of "Prejudiced Based Medicine" or "partial-EBM" (or EBM by "semi-systematic review"). I feel a more inclusive approach might be worthwhile. It is important to systematically and rigorously analyse all levels (or qualities) of available evidence. It is important that such an "evidence grid" approach is used for making important statements on treatments or outcomes, ranging from evidence of efficacy to clinical effectiveness and cost-effectiveness issues. In other words, what would the effect of including these other types of evidence be on the conclusions reached and what are the reasons for this? To simply use a reductionist model of analysing the best RCT's and offer this as conclusive evidence can be very misleading. For example in severe mental illness, RCT's with extensive exclusion criteria, even if of an excellent scientific quality, might have very little pragmatic use as the results might be difficult to generalise to the real world situation - for example other more pragmatic RCT's with wider inclusion criteria might well have higher drop-out rates but be more useful as they are closer to the "real world" situation. Some of Roy-Shapira's points regarding the hypertension and parachute scenarios touch on the important issue of the status of observational studies. I would add to this point that important lessons can come from the case report and case series study methods and small sample studies in increasing our evidence base. For example, less frequent complications associated with antipsychotic drugs such as neuroleptic malignant syndrome (NMS)and related hyperpyrexia syndromes, have initially been studied by this methodology. These studies are particularly useful in rarer conditions or complications, whereby larger RCTs or standard epidemiological approaches are prohibitively expensive and not feasible. Rather than not fully use such evidence in EBM, it would seem to me that an approach parallel (and of equal rigour) to that used for evaluating evidence from larger studies and RCT's needs to be promoted for small studies. Competing interests: None declared |
|||
|
|
|||
|
Lee A. Green, Associate Professor University of Michigan Dept of Family Medicine, 1018 Fuller campus 0708, Ann Arbor MI 48109
Send response to journal:
|
The article is very amusing, and it is tempting to remain in the same vein by offering the evidence-based observation that one does not need a parachute to skydive successfully... only to do it twice. However, this bit of satire points up a straw-man argument often raised against evidence- based medicine. EBM is not RCTs. That's probably worth repeating several times, because so often both EBM's detractors and some of its advocates just don't get it. Evidence is not binary, present or not, but exists on a heirarchy (Guyatt & Rennie, 2001). The top of the heirarchy is the blinded N-of -1 trial proving effectiveness in the particular patient, and next best is a meta-analysis of high-quality RCTs. At the bottom is subjectively interpreted uncontrolled experience. Both ends, and everything between, are evidence, differing only in reliability. The methods and rigor of EBM are nothing more or less than ways of correcting for our imperfect perceptions of our experiences. We prefer, cognitively, to perceive causal connections. We even perceive such connections where they do not exist, and we do so reliably and reproducibly under well-known sets of circumstances. RCTs aren't holy writ, they're simply a tool for filtering out our natural human biases in judgment and causal attribution. Whether it's necessary to use that tool depends upon the likelihood of such bias occurring. In some situations, no reasonably likely degree of bias can account for the results; e.g., falling from aircraft sans parachute, or penicillin for pneumococcal pneumonia. An RCT is unnecessary. Historical controls, which have a greater likelihood of false positive results than RCTs do, are adequate for the job. In some situations, concurrent cohort studies, which have a likelihood of false results greater than RCTs but less than historical controls, are sufficient, and sometimes only RCTs will do. The places where the highest-rigor methods are necessary are those with the highest likelihood of our fooling ourselves. Those are 1) when the "signal to noise ratio" is low, i.e., when we're looking for a small effect size or there is large natural variability in outcomes, and 2) where there is substantial motivation to find a positive result, i.e., where there is a significant component of advocacy. The evidence-based physician is not one who insists on RCTs, but one who climbs to the appropriate rung on the ladder of evidence. (These days that tends to be pretty high simply because most of the low- hanging fruit has already been picked.) The RCT-or-nothing nihilist and the data-proof reactionary probably deserve one another; let them have it out while the rest of us move beyond straw man debates. Guyatt G, Rennie D (eds.) Users' Guides to the Medical Literature: A Manual for Evidence-Based Practice. Chicago: AMA Press, 2001. Competing interests: None declared |
|||
|
|
|||
|
Scott D Ramsey, Associate Professor Fred Hutchinson Cancer Research Center, Seattle, USA, 98109
Send response to journal:
|
Parachutes may be a no-brainer, but this article is brainless. Let’s think of this issue a different way: When the airplane is crashing and death is imminent, one would not be stringent about evidence for a lifesaving technology, particularly if uncontrolled cohort studies showed 100% survival with the intervention (parachute) and 0% survival without. When the airplane is not crashing and jumping from an airplane is for a non-health issue (i.e., recreation), we might say buyer beware and hope the jumper can critically appraise the value of the technology. Unfortunately, there are few if any parallels to parachutes in health care. The danger with this type of article is that it can lead to labeling certain medical technologies as “parachutes” when in fact they are not. I’ve already seen this exact analogy used for a recent medical technology (lung volume reduction surgery for severe emphysema). In uncontrolled studies, it quite literally looked like everyone who didn’t die got better. When a high quality randomized controlled trial was done, the treatment turned out to have significant morbidity and mortality and a much more modest benefit than was originally hypothesized. Competing interests: None declared |
|||
|
|
|||
|
Terence Silverton, Hypnotherapist EN9 3AQ
Send response to journal:
|
Is there not some secondary gain for the parachutist Competing interests: None declared |
|||
|
|
|||
|
Jack E. Rosenblatt, M.D., Editor, Currents in Affective Illness Bethesda, MD 20817
Send response to journal:
|
Three statisticians were shivering in their blind early one morning, when a bevy of mallards began to descend on their decoys. One of them stood up, raised his shotgun, sighted on the largest duck, fired, and missed high; one of his companions followed, drew a bead (figuratively speaking), fired, and missed low. Ecstatic, the third jumped up and shouted, "Bullseye!" Competing interests: None declared |
|||
|
|
|||
|
Richard A. Davidson, MD,MPH, Distinguished Teaching Professor University of Florida College of Medicine Gainesville Fl 32610
Send response to journal:
|
This weak attempt at humor unfortunately reinforces one of the major negative sterotypes about EBM....that RCT's are required for evidence, and that observational studies are worthless. If only 10% of the therapies that are paraded in front of us by journals were as effective as parachutes, we would have much less need for EBM. The efficacy of most of our current therapies are only mildly successful. In fact, many therapies can provide only a 25% or less therapeutic improvement. If parachutes were that effective, nobody would use them. While it's easy enough to just chalk this one up to the cliche of the cantankerous British clinician, it shows a tremendous lack of insight about what EBM is and does. Even worse, it's just not funny. Competing interests: None declared |
|||
|
|
|||
|
Colin G Gibson, academic/practitioner (mental health nurse) University of Southampton
Send response to journal:
|
Its interesting to note the use of RCTs or the lack of them in this very important area. But being interested in human science (Heideggerian Hermenutics) I wonder of the authors considered the 'lived experience' of the use of a parachute (or not). Human science research often requires the use of 'reflection'. Could it be that the case sited by the authors (Cunningham A 2002) may have reflected upon his lived experiences of falling from a great height although the 'lived experience' may have been very brief. maybe a diary note or something like it. Colin Gibson PhD Competing interests: None declared |
|||
|
|
|||
|
Robert J. Temple, M.D., Associate Director for Medical Policy, CDER U.S. Food and Drug Administration, Rockville, MD 20857
Send response to journal:
|
The article by Smith and Pell [1], while obviously intended to amuse, can also be read as a criticism of the “evidence based medicine” crowd. At the risk of seeming over-sensitive and perhaps humorless, I want to point out that Smith and Pell are not confronting a genuine problem and I am concerned that their teasing could undermine appropriate attention to study design. Evidence-based medicine is never fully secure from attack by anecdote-based medicine. Their point is, of course, that the effectiveness of some interventions is so obvious that even purists should recognize that no randomized trial is necessary. To make that point, they utilize a straw man: the putative insistence on a controlled trial to evaluate the obvious effectiveness of parachutes. But what seems obvious is not always true and the doubters of the “obvious” are not necessarily hide-bound, rigid, or silly. Smith and Pell refer to the recent news about hormone replacement as having led to growing doubt about observational data, as, of course, it should have. But while no one would doubt that this experience supports the premise that “medical interventions based solely on observational data should be carefully scrutinized,” no one would go on to say that “the parachute is no exception.” In fact, in U.S. drug regulation, historically controlled trials are identified as one kind of “adequate and well-controlled study,” albeit one useful only in special cases, such as “diseases with high and predictable mortality (for example, certain malignancies) and studies in which the effect of the drug is self evident (general anesthetics, drug metabolism)”[2]. In an internationally accepted guidance document, ICH E10 (Choice of Control Group and Related Issues in Clinical Trials) [3], there is a lengthy discussion of how to assess the credibility of historically controlled studies, obviously indicating that they can be acceptable. In fact, single arm trials regularly provide the tumor response evidence that is a common basis for approval of new cancer drugs and such studies have been the basis of approval of drugs for metabolic stone disease and for inborn errors of metabolism, among other conditions. Still, a high degree of skepticism about uncontrolled observations is in order, and Smith and Pell’s (gently) mocking tone should not be allowed to obscure that. Apart from hormone replacement, an interesting case to consider is the use of early colloid replacement in people bleeding and hypotensive after a penetrating torso injury. A randomized trial [4] showed that such fluid replacement was harmful, certainly a surprise, as replacing fluid in someone in shock would seem to be as close to the parachute case as one could get. Data from non-randomized studies need to show sizable effects compared to historical or other control experience before they should be considered potentially valid evidence of effectiveness[5]. 1. Smith G and Pell J. Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomized controlled trials. BMJ 2003;327:1459-61. 2. Code of Federal Regulations. 21 CFR 314.126. Adequate and well controlled studies. http://www.access.gpo.gov/nara/cfr/cfr-table- search.html#page1. 3. International Conference on Harmonization. Guidance for Industry: E-10 Choice of control group and related issues in clinical trials. http:/www.fda.gov/cder/guidance/index.htm. 4. Bickell WH, Wall MJ, Pepe PE, Martin RR, Ginger VF, Allen MK, Mattox KL. Immediate versus delayed fluid resuscitation for hypotensive patients with penetrating torso injuries. NEJM 1994; 331:1105-9. 5. Temple R. Meta-analysis and epidemiologic studies in drug development and post-marketing surveillance. JAMA, 1999 Mar 3; 281(9):841 -844. Competing interests: None declared |
|||
|
|
|||
|
Jason D. Carroll, UHS-COM UHS-COM
Send response to journal:
|
Consider the topic at hand damaging to the extreme local parachute industry. At present three omnipresent powers control this world primarily through control of money, food, and thought. We now are lead to fight to the top of our respective heaps of dust and reflect that which we are told to idealize. When that is done, simply fade away. Do what you are told. Do you know you are doing what you are told? This great triumvirate controls without controling. So arriving back at the original topic, you end your fight by fading out. Lack of physical quantities nessesary for life to allow you to think towards fueling your ambition. It was always there, you never had it in your hand. Furious disgust in such a trivial mindset finally leads oneself to question life and report the findings in various ways. Then you die. No more parachutes. Competing interests: None declared |
|||
|
|
|||
|
Rajiv Sarin, Associate Professor, Radiation Oncology Tata Memorial Hospital, Parel, Mumbai, 400 012, India
Send response to journal:
|
This systematic review on parachutes appears to be an effort to highlight the nuances and complexities in implementing the modern mantra of evidence based medicine (EBM). In their concluding statement "We think that everyone might benefit if the most radical protagonists of evidence based medicine organised and participated in a double blind, randomised, placebo controlled, crossover trial of the parachute" the authors have used a medically improbable example to ridicule protagonists of EBM. However, they have not discussed the medical conditions and the type of interventions for which evidence from randomised controlled trial (RCT) is desirable. In fact some of the arguments are half truths and misleading. While their statement that free fall from a great height is not universally fatal is true, they do not mention the fact that free fall from heights where parachute is recommended is almost universally fatal (>99.9% fatal). Similarly their statement that parachutes are not universally effective is true but they fail to explicitly state that for a condition which is otherwise almost universally fatal, parachutes reduce the mortality by a thousand fold or more. For every freak case of free fall over land from over 1000 feet not resulting in death, there would be thousands of people who have survived gravitational challenges, presumably due to parachutes. In modern medicine such examples of highly effective life saving interventions in the face of near certain death are very rare except in certain traumatic conditions and some bacterial infections. I would be surprised if even the most ardent supporter of evidence based medicine would ever advocate randomised trial for interventions which in observational studies show remarkable efficacy in preventing near certain death. Unfortunately despite all the promises of modern medicine, additional benefit of any new intervention is very modest and that too with associated toxicity and costs. Do we have a choice of ignoring the power of large well conducted and pragmatic randomised trials whenever feasible in bringing us closer to the truth? Modern clinical trial methodology is bit like the democratic system of governance in the sense that they have inherent problems and attract criticism but under these circumstances there is hardly a worthy substitute. The need of the hour is to highlight the real problems and cost of conducting RCTs, clinical situations where they are superfluous or impossible to do rather than ridicule the protagonists of EBM with such medically improbable examples. No one really enjoys doing randomised trials- they are quite painful for the investigators, coordinators and the patients. Nevertheless, some things have to be done as they have to be done until someone comes out with a very clever idea which does not need a parachute to survive. Competing interests: None declared |
|||
|
|
|||
|
Richard G Fiddian-Green, None None
Send response to journal:
|
Many if not most major medical "advances" have never been subjected to a prospective randomised study before being introduced into routine management because their beneficial effects have been obvious. Examples include the appendectomy and the discovery of insulin and its development for the treatment of diabetes. Consider the consequences in the case of insulin. Decades after the adoption of insulin in routine care prospective randomised studies were done to improve the efficacy of its application in diabetic care. If insulin were discovered today would it be best if its application to patient care were to be deferred until the completion of such trials as were thopught to be necessary at the time and the subsequenct approval for use by a regulatory body and/or a healthcare tsar? If so how long would it take for the evidence base to be complete? More importantly could it ever be complete? In reading a book about the French Heugenots who arrived in England, Fiddian being said in our family records to be a derivative of Fideon, I was interested to learn that it had been estimated that some 70% of the English had acquired some Heugenot blood in succeeding two to three centuries. If so what proportion of the population will have acquired the recessive genes of juvenile diabetics one century after the introduction of insulin into routine medical care? More importantly, according to Tsar- Professor Sir George Alberti former President of the Royal College of Physicians, would be the extent to which the increasingly costly problem of type II diabetes might be the product of the same medical "advance". Might it be that 70% or more of the population will have acquired these recessive genes within one to three centuries? If so will humanity be better or worse off for the medical profession having introduced insulin into routine patient care? The case of appendectomy would seem much easier because not only can it be life-saving but also because it has no chance of having a long-term effect....unless the appendix does have an exotic but as yet undiscovered physiological property. Perhaps Professor Solomon Benatar, a juvenile diabetic and current President of the International Association of Bioethics, could provide us with an answer to the above questions. In so doing could he declare whether his answer applies to drug, dietary, and surgical treatments or whether he has different answers for each. Competing interests: None declared |
|||
|
|
|||
|
Grace E. Jackson, MD, none contract psychiatrist
Send response to journal:
|
Missing thus far is a broader discussion of the philosophical dimensions of EBM -- a point which I believe is the unspoken (perhaps overriding) agenda of the authors who conceived of this piece; and BMJ, for offering this article as a catalyst for further discussion. Evidence Based Medicine is a Postmodern phenomenon that encompasses aspects of a unique ontology (worldview) and epistemology (way of knowing - since the 1970s, a dependence upon the Randomized Controlled Trial). A cultural historian might suggest to us that Evidence Based Medicine has been the predictable outgrowth of Postmodernism -- that phase of human development associated with the confluence of logical positivism, biostatistics, digital technologies, and the nihilism that has arisen from the continuing tragedies of the nuclear age. What few physicians seem to contemplate is the possibility that the "acceptance" of EBM is inherently a philosophical (ontological) act. It rests upon the assumptions that Evidence CAN be determined, and that Evidence SHOULD be determined (and applied) as a basis for medical decision making. Few would doubt that physicians in the Industrialized World are currently expected to embrace the validity of each of these ontological assumptions. However, the epistemology of a distinctly Postmodern EBM is, I believe, something which has motivated the timing and saliency of the Parachute article to which we now respond. In the Postmodern landscape, Evidence has come to be based upon quantities, similarities, populations, and averages -- rather than qualities, idiosyncracies, individual narratives, and specifics. This medical epistemology might not be so critical, were it not for the ethical crises which now denude the integrity of the prevailing Evidence: 1) publication bias; 2) concealment of negative findings (file drawer effect; 3) manipulations in clinical research designs (placebo washouts, preference for LOCF vs. OC outcomes, non-comparative dosing strategies, underpowered studies, paltry effect sizes.) Recognizing the dubious reliability of the Evidence upon which clinical practice has increasingly come to depend (e.g., the information presented by journals, textbooks, government agencies, the news media), the time has come for physicians to contemplate the ramifications of Postmodern philosophy within their profession. It is time for providers to reassess the value of direct observation, and to trust more readily both the empirical and intuitive discoveries they make each day in their personal experience (even if those discoveries are contradicted by the "best available Evidence"). Though Smith and Pell speak to us from behind the veil of parody, there could be nothing more serious at this juncture than their call for healers to reconsider what it means to be authentic and true. Competing interests: None declared |
|||
|
|
|||
|
Paul R. Chelminski, Assistant Professor of Medicine University of North Carolina, Chapel Hill, NC 27599
Send response to journal:
|
Smith and Pell's call for a randomized controlled trial of parachute efficacy is visionary. The authors, however, underestimate the difficulty in obtaining the approval of an institutional review board for the use of human subjects in such an experiment--no matter how antipathetic the board might be towards the devotees of evidence-based medicine, volunteers or not. In order to test this important hypothesis, I recommend using a variety of animals pushed from the cargo doors of specially outfitted troop transports. Higher primates and lesser animals could be randomized to parachute or free fall. The use of a variety of animals would permit the proper statistical extrapolation to humans. I also recommend using "active controls," such as chickens or guinea fowl randomized to parachute or free fly.Although animal rights advocates might protest this experiment, it could probably be executed without too much controversy in a developing country anxious for the collateral economic benefits of research and academic prestige. Competing interests: I am not a vegetarian. |
|||
|
|
|||
|
Howard McNulty, Visiting Professor Dept Pharmaceutical Sciences University of Strathclyde G4 0NR
Send response to journal:
|
This is a rapid response(!) having just read this thought provoking article and earlier contributors. In the lighter vein, if parachutes really are effective why do airlines not provide them - they are potentially more use than lifejackets, which have no evidence base for crash landings on the ground. Their introduction would make the pre-flight briefing much more interesting. More seriously, perhaps one outcome is we should ask where is the Evidence Base for the place of EBM? There undoubtedly is a need for help in deciding risks and benefits of marginal effects. However, data can only be gathered by observation in some areas, such as studies in premature babies or treatments of very rare conditions. Much of paediatric medicine operates from previous observations and many medicines are used outside their market authorisation by paediatricians. This does not break any laws and is potentially life saving. On the other side of the coin, often significant differences statistically in trials are not significant clinically. Products legitimate claims to increase outcomes by 100% could only increase lives saved from 12 to 24 per 1,000 at a very high cost. Clinical trials in volunteers may bear little relation to to real patients. Cancer risks 100% higher by rising from say 10 to 20 per 100,000 often hit the news headlines. So, are we in need of a reality check? Have Smith and Pell cleverly started a process of deciding where Evidence Based Practice best fits? I hope so. Competing interests: None declared |
|||
|
|
|||
|
John Tukey, Professor emeritus USA 06051
Send response to journal:
|
Maybe they should have used Stata 8. Competing interests: None declared |
|||
|
|
|||
|
Julius Atashili, MD, MPH student University of North Carolina Chapel HIll, NC 27516
Send response to journal:
|
Let me begin by saying that I do not intend to address the debate on whether or not male circumcision should be offered as a public health intervention to reduce HIV transmission. However, I am surprised that repeatedly one of the main arguments against this has been the "absence of randomized clinical trials". In fact to quote a cochrane review, ‘Despite the positive results of a number of observational studies, there are not yet sufficient grounds to conclude that male circumcision, as a preventive strategy for HIV infection, does more good than harm. The results of current ongoing RCTs will need to be carefully considered before circumcision is implemented as a public health intervention for prevention of sexually transmitted HIV’ (Sigfried et al., 2003). Here is a disease for which there were an estimated 4.8 million new infections in the year 2003 (UNAIDS, 2004) and I ask myself if we can afford to wait for randomized clinical trials. No stone should be left unturned in the fight against the HIV pandemic. The absence of RCTs on parachute use never precluded their use. Just like parachute use, and considering the currently available evidence from observational studies, the use of male circumcision to reduce HIV transmission should be based on technical feasibility determinants and not wait for RCTs. 1.Siegfried N, Muller M, Volmink J, Deeks J, Egger M, Low N, Weiss H, Walker S, Williamson P. Male circumcision for prevention of heterosexual acquisition of HIV in men (Cochrane Review). In: The Cochrane Library, Issue 3, 2003. Oxford: Update Software. 2.UNAIDS. 2004 report on the global HIV/AIDS epidemic : 4th global report. Competing interests: None declared |
|||
|
|
|||
|
Larry M. Weisenthal, Medical Director/Laboratory Director Weisenthal Cancer Group 16512 Burke Lane Huntington Beach, CA, USA 92647
Send response to journal:
|
I interpret the parachute study as illustrating that, in life or death situations, one must make judgements based upon preponderance of available evidence as opposed to proof beyond reasonable doubt. It seems obvious, but the parachute study makes the point that "evidence-based medicine" proponents may fail to apply this common sense standard on a consistent basis. To cite just one example, the American Society of Clinical Oncology established a policy recommending against the use of cell culture drug resistance testing (CCDRT) as an aid to drug selection in cancer chemotherapy, based on reviews (refs. 1,2) which specifically excluded from consideration studies reporting the predictive accuracy of CCDRT (of which there were many), and including only studies relating to the "efficacy" of CCDRT in improving treatment outcomes (of which there were virtually none). This was especially curious, as predictive accuracy is the chief criterion traditionally used to validate all laboratory tests currently in use in cancer medicine (including hormone receptors, Her2/neu, gene expression-based assays, and all immunohistochemical staining tests). Were proof of efficacy (particularly in prospective, randomized trials) to be the standard for evaluating laboratory tests, then clinical oncologists should immediately abandon all the laboratory tests currently used in the management of cancer patients, as no tests would pass this standard. Clinical oncology investigators have too often descended into an exhaustive study of hypotheses which are ultimately of limited importance. Many cancer treatments are of such limited effectiveness that they do not deserve to be protected from the competition of other approaches which are well grounded in peer review science, but which have not yet met the most demanding standards of "evidence based medicine." Larry M Weisenthal MD PhD
Literature Cited: 1. Schrag D, Garewal HS, Burstein HJ, Samson DJ, Von Hoff DD, Somerfield MR. American Society of Clinical Oncology technology assessment: chemotherapy sensitivity and resistance assays. J Clin Oncol 22:3631-8, 2004. 2. Samson DJ, Seidenfeld J, Ziegler K, and Aronson N. Chemotherapy sensitivity and resistance assays: a systematic review. J Clin Oncol 22:3618-30, 2004 Competing interests: I direct a private clinical reference laboratory which provides cell culture drug resistance testing as a service to patients and oncologists. (information at http://weisenthal.org ) |
|||
|
|
|||
|
C Williams, H3 FL TRB;PPL-instrument; Los Angeles 90272
Send response to journal:
|
Thank you for this study. Subsequent to publication, the use of parachutes by hang glider pilots in Southern California has been abandoned. Many of us felt they were bulky anyway, and recognition of the lack of randomized trials opened our eyes. Most hang glider pilots here subscribe only to the New England Journal of Medicine and JAMA, so we came very near missing this paper. Upon considering the hegenomy of the Parachute Industry, perhaps the suppression of information was not accidental. Thank you again. C Williams Competing interests: None declared |
|||
|
|
|||
|
GS Umamaheswara Rao, Professor of Neuroanaesthesia National Institute of Mental Health and Neurosciences Bangalore India 560 029
Send response to journal:
|
A satire as it appears on the surface of it, Smith and Pell's article reflects the serious side of our obsession with Evidence Based Medicine. The fundamental issue is what is it that we call as evidence. If it is the class I evidence supported by multicentre double blind randomised clinical trials, how many of our day to day well-accepted practices are supported by such evidence? Do we have to go back and create evidence to show that morphine is an analgesic or mannitol decreases brain oedema? If we have to depend solely on Class I evidence, do we have such evidence on all those thousands of clinical issues that we deal with everyday? What do we do until we have that evidence? Given the financial implications of multicentre randomised trials, is it ever possible to have that kind of evidence on all the issues? We must understand that, as of today, even the best of the clinical practice guidelines are often influenced by a handful of studies. If our definition of evidence is not flawed, why is that year after year we have so many studies ending up with negative results - studies that have been started right honestly based on strong evidence from experimental and single centre clinical trials? Does it mean that all those experimental and single centre clinical trials are uniformly flawed? Does it mean that we are always asking wrong or irrelevant questions most often when we start a multicentre randomised trial? Or is there something wrong with the way the multicentre randomised trials are conducted? Have we not come across inter-institutional differences among the results of major randomised trials? Have we not seen the co-coordinators of these trials agree that the experience of the individual institutions strongly influences the results? If such are the fallacies of these studies how do we base our clinical practices on these trials? To put it in other words, under the cover of good evidence, are we systematically killing all the potential therapies and advocating therapies that are only to be proven wrong in course of time? I have witnessed patients in whom nitric oxide improved oxygenation and prevented them from succumbing immediately to life-threatening hypoxia caused by acute respiratory distress syndrome (ARDS), before the large randomised trials were published. Based on the good evidence that later showed no improvement in clinical outcomes with nitric oxide, should I have denied these patients this beneficial therapy? The reason for the whole malady probably lies somewhere in the process of generation of this Class I evidence. Should we look at that more critically? Agreed that medicine should not be left to the whims and fancies of individual physicians. But time has come for us to seriously ponder over our definitions of Evidence and probably to very meticulously supervise the process leading to generation of this evidence. Competing interests: None declared |
|||
|
|
|||
|
Peter A Dulimov, Programmer, Clinical Engineering Research ResMed, Sydney Australia, 2153
Send response to journal:
|
Prior to taking my current job, I had worked for a number of military businesses. There are many applications for a technique for making inferences from noisy and incomplete data in that domain, and I often wondered why life sciences people did not use the same tools that we did, ie., Bayesian methods. It occurs to me now that the answer to my question is that in the particular applications that I worked with, we had good models of the phenomena we were interested in based on solid physics. In the past, the life sciences were not so similarly blessed, and so presumably were forced to persevere with classical statistics. The obvious exceptions, like trauma caused from extreme deceleration of the body from very high speed, have a model where even software programmers such as myself understand the consequences of making no intervention to a patient with substantial continuing blood loss and severe soft tissue damage. Bayesian methods would indicate making a decision in favour of intervention even in the case of the Smith and Pell paper. The more interesting point is that in many areas of the life sciences, it seems that researchers are now in possession of pretty good models of even complicated biological phenomena. That opens up the possibility of using Bayesian methods in those areas. As Laplace (the real genius behind Bayesian methods) is purported to have said: "Probability is nothing more than the quantification of common sense." Give it a try. Competing interests: None declared |
|||
|
|
|||
|
Sharon R Bridgeman, Acupuncturist in private practice Laidley, Queensland 4341 Australia
Send response to journal:
|
I have the following questions and comments for those more qualified than myself to address with reference to EBM: 1) The human being is not a static machine entity, but rather a mix of complex and adaptable systems of the physical and metaphysical wrapped up in a skin jacket; how therefore, is it possible to hold all else equal and move only one variable and measure the outcome and attribute that outcome to that one variable and then apply the whole concept back to this physical and metaphysical being in a skin jacket? 2) How is it possible to map the geometric consequences of the treatment researched or given? For instance the introduction of the motor vehicle 'solved' the manure pollution problem created by the use of horses in city streets. However, the solution of the motor vehicle has gone on to create more and greater problems than it ever solved. At the time of the introduction of the motor vehicle it was not possible to know these geometric consequences. Therefore what if the effect of children's vaccines is a higher incidence of SIDS, or the lack of a protein means that the high level of mercury in vaccines cannot be removed by some individuals and there is a non-genetic increase in the incidence of autism? By the way, where are the studies of safety and efficacy on any vaccine in use today or at any time in history? 3. Health is a big dollar business, with vested interest. How is it possible not to be influenced by the almighty dollar? If the common Turmeric can kill HPV where is the money to be made compared to using a patent vaccine(1)? 4. How is it possible, within the scope of EBM, to ignore the damage of the side effects of medication and surgery? Blindness attributed to the use of corticoid steroids? Heart muscle damage caused by the use of lipitor type drugs? The MIMS is full of the collateral damage done by medication. How does EBM make such damage acceptable? In terms of surgery, how is that by removing the offending part is there a cure? In my 12 years in practice I have seen many women present minus their reproductive organs as a form of treatment, but never in that time have I seen a man present with the removal of his reproductive organs as a form of treatment. It is of course possible in the instance of a motor vehicle, to surgically remove the cable connecting the engine’s thermometer to the reading instrument on the dash board, however, the cause of the over heating engine has yet to be diagnosed let alone treated. 5. What then is EBM? A treatment that does harm and has some effect on the target tissue? Yet who determines the levels of harm and level of effect, and who keeps tract of all the collateral damage? Once upon a time, I was told, that one only paid one’s physician when they were well, and stopped paying them once they were sick. Now wouldn’t that be a shot in the arm for preventative medicine, with those earning the most and having the most work-free time, because they were able to keep their patients well! 1 http://www3.interscience.wiley.com/cgi- bin/abstract/109742042/ABSTRACT Biochemical and Biophysical Research Communications 326, 472 (2005) Link to abstract International Journal of Cancer 113, 951 (2005) Link to abstract Journal of Biological Chemistry 279, 51163 (2004) Link to abstract Competing interests: Assumption: That it is possible to stimulate the initate healing ability of the human being to what ever extent without intervention to toxic substances (drugs) and surgical removal of symptoms |
|||
|
|
|||
|
Timothy R. Church, Professor University of Minnesota School of Public Health
Send response to journal:
|
On one level, this is a funny article. I chuckled when I first read it. On reflection, however, I thought "Well, maybe not," because a lot of people have died based on physicians' arrogance about their ability to judge the efficacy of a treatment based on theory and uncontrolled observation. Several high profile medical procedures that were "obviously" effective have been shown by randomized trials to be (oops) killing people when compared to placebo. For starters to a long list of such failed therapies, look at antiarrhythmics for post-MI arrhythmias, prophylaxis for T. gondii in HIV infection, and endarterectomy for carotid stenosis; all were proven to be harmful rather than helpful in randomized trials, and in the face of widespread opposition to even testing them against no treatment. In theory they "had to work." But didn't. But what the heck, let's play along. Suppose we had never seen a parachute before. Someone proposes one and we agree it's a good idea, but how to test it out? Human trials sound good. But what's the question? It is not, as the author would have you believe, whether to jump out of the plane without a parachute or with one, but rather stay in the plane or jump with a parachute. No one was voluntarily jumping out of planes prior to the invention of the parachute, so it wasn't to prevent a health threat, but rather to facilitate a rapid exit from a nonviable plane. Another weakness in this straw-man argument is that the physics of the parachute are clear and experimentally verifiable without involving humans, but I don't think the authors would ever suggest that human physiology and pathology in the face of medication, radiation, or surgical intervention is ever quite as clear and predictable, or that non-human experience (whether observational or experimental) would ever suffice. The author offers as an alternative to evidence-based methods the "common sense" method, which is really the "trust me, I'm a doctor" method. That's not worked out so well in many high profile cases (see above, plus note the recent finding that expensive, profitable angioplasty and coronary artery by-pass grafts are no better than simple medical treatment of arteriosclerosis). And these are just the ones for which careful scientists have been able to do randomized trials. Most of our accepted therapies never have been subjected to such scrutiny, but it is breathtaking how frequently such scrutiny reveals problems. Thanks, but I'll stick with scientifically proven remedies. Competing interests: None declared |
|||
|
|
|||
|
Nibu .A . George, Scientist Department of Biomedical Engineering, University Medical Center Groningen, 9713AV Groningen
Send response to journal:
|
Comment on: Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials Nibu A George Department of Biomedical Engineering University Medical Center Groningen and University of Groningen 9713AV Groningen, The Netherlands e-mail: n.a.george@med.umcg.nl Abstract Randomised controlled trials to prove the effectiveness of a medical intervention is not necessary if it can be proved with the help of fundamental theoretical analysis and or with the identical problems that are well established. Introduction Smith et al challenged the effectiveness of parachutes in saving human life claiming that no controlled randomised trials have been conducted to prove it [1]. The authors also claim that the perception that the parachutes are a successful intervention is merely based on a casual observation rather than a rigorous scientific analysis. In order to support their claim the have used some reports of morbidity and mortality associated with the failure or iatrogenic complications of the intervention [see ref 1-4 in the above ref.]. In this paper we would like to answer to the questions raised by the above authors using the fundamental laws of physics. Discussion Reply to: Evidence based pride and observational prejudice Based on reference 7 in the above quoted manuscript, the authors concluded that all medical interventions justified by observational data need verifications through randomised controlled trials. In fact the article they quoted was referring to few different pure medical cases to describe the biasing in data analysis. Here we like to point out few things. First of all generalizing such reports of some selected cases and making it a universal truth is unhealthy and challenging the entire scientific community. Secondly, the comparing the parachute scenario with a pure medical situation is unacceptable since the parachute jump is rather a physical situation and it become a medical situation only if the jump caused any physical harm to the person involved. Reply to: Natural history of Gravitational Challenge Based on some references, the authors claimed that the effectiveness of an intervention needs to be judged with a non-intervention. The authors used few manually selected cases to prove the success of free fall without a parachute and fatal jumps involving parachutes. Ironically, the data biasing discussed above is more applicable here. Number of people jump every day with the help of parachutes and any successful jump is not recorded in any medical or scientific literature, simply because it has no significance. On the other hand, large number of people dies everyday worldwide resulting from trauma caused by free fall from heights of few meters to several tens of meters. In fact, here the authors approached the present problem with a clear prejudice in their mind and consequently they picked up some exceptional historical evidences that match their claim. Reply to: The parachute and healthy cohort effect The authors compared the individuals jumping from an aircraft without a parachute as high psychiatric morbidity group relative to individuals who perform a parachute assisted jump. But the conclusion that parachutists enjoy the protective effect of the “healthy cohort” effect of the group of individuals who possess less psychiatric morbidity is absolutely baseless and challenging the commonsense of the entire scientific community. Dragging the role of “income” and “cigarette use” into the protection gained from scientific inventions such as parachutes are questionable. The “healthy cohort” effect in cardiac deceases etc due to the proper exercise, dieting, better life style etc of a group of a individuals are not comparable to the present parachute scenario. Reply to: The medicalisation of free fall The authors statement of induced fear and dependency and doctors obsession with the parachutes due to its wide spread use are also questionable. This situation can be compared to crossing a road. Although it is only meant to cross the road during a green signal, it could be possible sometimes to safely cross even in red signal. But an individual crossing during a red signal may be more nervous and cautious and this cannot be simply neglected as an induced fear, but it is a fact that this particular individual can harm himself or others by his act. Following a traffic rule does not require any randomised controlled trials to prove its effectiveness and mental and physical protection that offers to each and every individual. Reply to: Parachutes and military industry complex Any technological and product development involves man power and financial expenses and all successful industries exist simply because they make profit from their business. Many of the widely used medical interventions such as X-rays, radiation therapy, and many of the drugs used for treatments have adverse short and long term side effects. But that does not stop people from using them, even if they are aware of the side effects. Then what is the meaning of any randomised controlled trials to prove the success or failure rate of parachutes as a life saving intervention. Reply to: A call to (broken) arms Not the common sense but simple laws of physics can prove the effectiveness of the parachute as a life saving intervention. When a person jumps from a height accelerates towards the earth and eventually reaches the “terminal velocity”. For an average person this terminal velocity is about 200km/hour and it takes only about 3 seconds to reach the terminal velocity. The damages caused to an individual hitting the ground at this speed is not just broken arms! Now, introducing a parachute reduces this terminal velocity to less than 10km/hour. This is comparable to crashing an old car without any airbags to a solid concrete wall at 200km/h and 10km/h. Reference 1. Smith G C S and Pell J P. Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials. British Journal of Medicine 2003; 327: 1459-1461. Competing interests: None declared |
|||
|
|
|||
|
Phil Goetz, Bioinformatics engineer JCVI
Send response to journal:
|
I find it odd that, with so many responses, no one has addressed the issue of how the intended use of a trial outcome affects the choice of methodology. The dialogue so far assumes that the question is therepeutic: Should a doctor recommend one therapy over another? The reality is that another important use of randomized trials is for regulation and insurance. Randomized trials are required for a drug to be legal, and for a drug or procedure to be paid for by insurance. The proper analogy to make is not whether it is sensible to use a parachute before jumping out of an airplane in the absence of randomized trials. The more relevant analogies are: 1) Is it proper for insurance companies to help pay for the cost of parachutes? (For this analogy to work, we must assume that it is known before takeoff that the plane will crash, and that it must take off anyway.) For the answer to be "yes", we should require more proof of efficacy than for the therapeutic question. 2) Is it proper for the government to forbid the use of parachutes in the absence of randomized trials? For the answer to be "yes", we should require more proof of inefficacy than for the therapeutic question. The discussion of the parachute question has focused on the question of effectiveness, without any mention of the regulation which (if this were a serious medical issue) would be the main outcome of the discussion. Likewise, many debates about controversial drugs have a clear answer if you realize that the question being asked is not just "is this drug effective?" but also "should use of this drug be legal?" The debate takes place framed as if it were a debate about therapy; the results are used as if it had been a debate about regulation; and the result is too much regulation. Competing interests: None declared |
|||