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Kalender |
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Nieuws op de Muur rip-off |
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| Sassia |  | vrijdag 15 mei 2009, 9:31:54
Ik wil koffieeeeeee |
| Jeroen |  | vrijdag 15 mei 2009, 9:25:19
Moggûh! |
| Pipster |  | vrijdag 15 mei 2009, 1:22:02
42 
shellac  |
| Manon |  | donderdag 14 mei 2009, 22:14:45
@42: |
| Jeroen | | donderdag 14 mei 2009, 21:59:15
Heel knap gedaan, 42!! Gefeliciteerd!  |
| 42 |  | donderdag 14 mei 2009, 19:34:31
gelukt! www.joninorah.com  |
| Rick |  | donderdag 14 mei 2009, 17:04:29
Nice brain bug... |
| Mara |  | donderdag 14 mei 2009, 13:03:39
Een festival op woensdag is misschien wat heftig... Maar toch wel weer een aardig bandje gezien..
Mara heeft ook een homepage: http://www.monkeybusiness.cz/en_index.htm (534 keer geklikt) |
| Manon | | donderdag 14 mei 2009, 12:08:23
[gniffel]zie ik daar een zwak zonnetje?[/gniffel]
Ach, als alles wel door was gegaan was ik nu ook klaar geweest |
| Svalby |  | donderdag 14 mei 2009, 10:55:44
morrie |
| Manon | | donderdag 14 mei 2009, 10:18:02
Goedemorgen Muurbloempjes!
Ineens een vrije dag omdat de sportdag afgelast werd en er geen alternatief programma was
 |
| Jeroen | | donderdag 14 mei 2009, 9:11:36
Moggûh Muur. 
#SftP: Ik ben ook nog niet helemaal zeker, hoor. Wellicht dat er een film gepakt gaat worden. |
SftP bb  |  | donderdag 14 mei 2009, 9:06:03
@Jeroen & nemo: Ik heb andere 'uitje' van vrijdag afgezegd. Kans dat het Victorie wordt is nu realistisch... |
| un-que | | donderdag 14 mei 2009, 6:39:13
hoei! morrie! |
| SftP |  | woensdag 13 mei 2009, 19:29:21
12:42:52 waarschijnlijk heb ik iets anders. Als dat niet doorgaat, ga ik naar Victorie.... 5% kans |
| ludo |  | woensdag 13 mei 2009, 17:03:38
Wat een leuke Xoox quiz deze maand
Ik doe hem nu pas |
| Worm |  | woensdag 13 mei 2009, 17:01:01
Ah! Dank u hartelijk! |
| Barf |  | woensdag 13 mei 2009, 15:42:33
Couplet:
|F |Gm |Am |Bb |
|F |Am |Dm |Bm7b5 |Bb |C |C |
Refrein:
|F |Dm7 |Am7 |Bb C |
|F |Dm7 |Am7 |Bb C |Dm C |
Iets dergelijks... |
| Worm | | woensdag 13 mei 2009, 15:24:42
lol. Zeg, heeft iemand toevallig de akkoorden van 'Play it cool' van Freiheit? Veel fauter kan het niet worden, derhalve een fantastisch nummer. Kan alleen de chords niet vinden en ben te lui om zelf uit te zoeken... |
| Jeroen | | woensdag 13 mei 2009, 15:18:24
Nou, hij herkende toch mooi wel mijn met de spatiebalk uitgevoerde versie van Smoke on the Water. En da's toch best een lastige.  |
| Worm | | woensdag 13 mei 2009, 15:16:05
Grappig... Klopt alleen geen moer van, maar wel leuk...
Worm heeft ook een homepage: http://www.bored.com/songtapper/ (568 keer geklikt) |
| Jeroen | | woensdag 13 mei 2009, 12:46:55
Hallo! Gloeten telug!  |
| pipapogo |  | woensdag 13 mei 2009, 12:44:35
[spleetogensmiley] Ni Hao! [/spleetogensmiley] Groeten uut China! Het is hier tof  Echt master! |
| Jeroen | | woensdag 13 mei 2009, 12:23:04
Ik vind dingen niet zo snel grappig, hoor. Ik ben een chagrijnige lul.  |
| Rick | | woensdag 13 mei 2009, 12:02:42
11:12:34 De titel was nog niet grappig genoeg? |
| Mara | | woensdag 13 mei 2009, 11:30:48
Smoking is the the main reason for statistics...
|
| P |  | woensdag 13 mei 2009, 11:30:44
BMJ 2003;327:1459-1461 (20 December), doi:10.1136/bmj.327.7429.1459
Hazardous journey
Parachute use to prevent death and major trauma related to gravitational challenge: systematic review of randomised controlled trials
Gordon C S Smith, professor1, Jill P Pell, consultant2
1 Department of Obstetrics and Gynaecology, Cambridge University, Cambridge CB2 2QQ, 2 Department of Public Health, Greater Glasgow NHS Board, Glasgow G3 8YU
Correspondence to: G C S Smith gcss2@cam.ac.uk
Abstract
Objectives To determine whether parachutes are effective in preventing major trauma related to gravitational challenge.
Design Systematic review of randomised controlled trials.
Data sources: Medline, Web of Science, Embase, and the Cochrane Library databases; appropriate internet sites and citation lists.
Study selection: Studies showing the effects of using a parachute during free fall.
Main outcome measure Death or major trauma, defined as an injury severity score > 15.
Results We were unable to identify any randomised controlled trials of parachute intervention.
Conclusions As with many interventions intended to prevent ill health, the effectiveness of parachutes has not been subjected to rigorous evaluation by using randomised controlled trials. Advocates of evidence based medicine have criticised the adoption of interventions evaluated by using only observational data. 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.
Introduction
The parachute is used in recreational, voluntary sector, and military settings to reduce the risk of orthopaedic, head, and soft tissue injury after gravitational challenge, typically in the context of jumping from an aircraft. The perception that parachutes are a successful intervention is based largely on anecdotal evidence. Observational data have shown that their use is associated with morbidity and mortality, due to both failure of the intervention1 2 and iatrogenic complications.3 In addition, "natural history" studies of free fall indicate that failure to take or deploy a parachute does not inevitably result in an adverse outcome.4 We therefore undertook a systematic review of randomised controlled trials of parachutes.
Methods
Literature search
We conducted the review in accordance with the QUOROM (quality of reporting of meta-analyses) guidelines.5 We searched for randomised controlled trials of parachute use on Medline, Web of Science, Embase, the Cochrane Library, appropriate internet sites, and citation lists. Search words employed were "parachute" and "trial." We imposed no language restriction and included any studies that entailed jumping from a height greater than 100 metres. The accepted intervention was a fabric device, secured by strings to a harness worn by the participant and released (either automatically or manually) during free fall with the purpose of limiting the rate of descent. We excluded studies that had no control group.
Definition of outcomes
The major outcomes studied were death or major trauma, defined as an injury severity score greater than 15.6
Meta-analysis
Our statistical apprach was to assess outcomes in parachute and control groups by odds ratios and quantified the precision of estimates by 95% confidence intervals. We chose the Mantel-Haenszel test to assess heterogeneity, and sensitivity and subgroup analyses and fixed effects weighted regression techniques to explore causes of heterogeneity. We selected a funnel plot to assess publication bias visually and Egger's and Begg's tests to test it quantitatively. Stata software, version 7.0, was the tool for all statistical analyses.
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| P | | woensdag 13 mei 2009, 11:30:38
Oeps, sorry.. Komt ie dan:
Results
Our search strategy did not find any randomised controlled trials of the parachute.
Parachutes reduce the risk of injury after gravitational challenge, but their effectiveness has not been proved with randomised controlled trials
Credit: HULTON/GETTY
Discussion
Evidence based pride and observational prejudice
It is a truth universally acknowledged that a medical intervention justified by observational data must be in want of verification through a randomised controlled trial. Observational studies have been tainted by accusations of data dredging, confounding, and bias.7 For example, observational studies showed lower rates of ischaemic heart disease among women using hormone replacement therapy, and these data were interpreted as advocating hormone replacement for healthy women, women with established ischaemic heart disease, and women with risk factors for ischaemic heart disease.8 However, randomised controlled trials showed that hormone replacement therapy actually increased the risk of ischaemic heart disease,9 indicating that the apparent protective effects seen in observational studies were due to bias. Cases such as this one show that medical interventions based solely on observational data should be carefully scrutinised, and the parachute is no exception.
Natural history of gravitational challenge
The effectiveness of an intervention has to be judged relative to non-intervention. Understanding the natural history of free fall is therefore imperative. If failure to use a parachute were associated with 100% mortality then any survival associated with its use might be considered evidence of effectiveness. However, an adverse outcome after free fall is by no means inevitable. Survival has been reported after gravitation challenges of more than 10 000 metres (33 000 feet).4 In addition, the use of parachutes is itself associated with morbidity and mortality.1-3 10 This is in part due to failure of the intervention. However, as with all interventions, parachutes are also associated with iatrogenic complications.3 Therefore, studies are required to calculate the balance of risks and benefits of parachute use.
The parachute and the healthy cohort effect
One of the major weaknesses of observational data is the possibility of bias, including selection bias and reporting bias, which can be obviated largely by using randomised controlled trials. The relevance to parachute use is that individuals jumping from aircraft without the help of a parachute are likely to have a high prevalence of pre-existing psychiatric morbidity. Individuals who use parachutes are likely to have less psychiatric morbidity and may also differ in key demographic factors, such as income and cigarette use. It follows, therefore, that the apparent protective effect of parachutes may be merely an example of the "healthy cohort" effect. Observational studies typically use multivariate analytical approaches, using maximum likelihood based modelling methods to try to adjust estimates of relative risk for these biases. Distasteful as these statistical adjustments are for the cognoscenti of evidence based medicine, no such analyses exist for assessing the presumed effects of the parachute.
The medicalisation of free fall
It is often said that doctors are interfering monsters obsessed with disease and power, who will not be satisfied until they control every aspect of our lives (Journal of Social Science, pick a volume). It might be argued that the pressure exerted on individuals to use parachutes is yet another example of a natural, life enhancing experience being turned into a situation of fear and dependency. The widespread use of the parachute may just be another example of doctors' obsession with disease prevention and their misplaced belief in unproved technology to provide effective protection against occasional adverse events.
What is already known about this topic
Parachutes are widely used to prevent death and major injury after gravitational challenge
Parachute use is associated with adverse effects due to failure of the intervention and iatrogenic injury
Studies of free fall do not show 100% mortality
What this study adds
No randomised controlled trials of parachute use have been undertaken
The basis for parachute use is purely observational, and its apparent efficacy could potentially be explained by a "healthy cohort" effect
Individuals who insist that all interventions need to be validated by a randomised controlled trial need to come down to earth with a bump
Parachutes and the military industrial complex
However sinister doctors may be, there are powers at large that are even more evil. The parachute industry has earned billions of dollars for vast multinational corporations whose profits depend on belief in the efficacy of their product. One would hardly expect these vast commercial concerns to have the bravery to test their product in the setting of a randomised controlled trial. Moreover, industry sponsored trials are more likely to conclude in favour of their commercial product,11 and it is unclear whether the results of such industry sponsored trials are reliable.
A call to (broken) arms
Only two options exist. The first is that we accept that, under exceptional circumstances, common sense might be applied when considering the potential risks and benefits of interventions. The second is that we continue our quest for the holy grail of exclusively evidence based interventions and preclude parachute use outside the context of a properly conducted trial. The dependency we have created in our population may make recruitment of the unenlightened masses to such a trial difficult. If so, we feel assured that those who advocate evidence based medicine and criticise use of interventions that lack an evidence base will not hesitate to demonstrate their commitment by volunteering for a double blind, randomised, placebo controlled, crossover trial.
--------------------------------------------------------------------------------
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. |
| Jeroen | | woensdag 13 mei 2009, 11:12:34
Goed man, links plaatsen achter een login! 
Anyways: moggûh! |
| Rick | | woensdag 13 mei 2009, 11:10:26
 |
| P | | woensdag 13 mei 2009, 10:38:08
Waar is eigenlijk de bloei-smiley ? |
| Svalby | | woensdag 13 mei 2009, 9:24:21
echt niet!
mogguh mense 
Die oude Therapy? gasten rockten gisteren   |
| pipje | | woensdag 13 mei 2009, 9:07:57
bloeien is zo overrated
mogguh! |
| unk | | woensdag 13 mei 2009, 8:17:19
hoei! morrie! |
| CCcc | | dinsdag 12 mei 2009, 22:43:47
woei Tatu! |
| Cccc | | dinsdag 12 mei 2009, 21:42:30
hihi nd eurovision2009  |
| CCcc | | dinsdag 12 mei 2009, 21:41:45
best een leuk nummer dat van Turkije |
| Lonn |  | dinsdag 12 mei 2009, 19:15:31
Middag! |
| Mara | | dinsdag 12 mei 2009, 19:08:42
Waar zijn de tijden dat er elke 30 seconden wel weer iets werd gepost op deze muur... 
Goed... Op naar huis (=cafe).
Ciao |
| Mara |  | dinsdag 12 mei 2009, 18:59:30
Goedenavond deze avond |
| unk | | dinsdag 12 mei 2009, 18:45:08
Ha, ze denken ook aan alles bij de Amerikaanse televisie |
| Lurk |  | dinsdag 12 mei 2009, 18:38:30
TV On The Radio - DLZ | |
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