Vaccinations and Parachutes

A new paper calls for “double blind, randomised, placebo controlled, crossover trial of the parachute.” 

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

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. We therefore undertook a systematic review of randomised controlled
trials of parachutes.

After an exhaustive literature search they found the following:

Our search strategy did not find any randomised controlled trials of the parachute.

There follows a discussion that includes the subtopics “Natural history of gravitational challenge”, “The parachute and the healthy cohort effect”, and “Parachutes and the military industrial complex”, they conclude with:

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.

This is exactly the situation that anti-vaxxers call for. Vaccines have found to be one of the greatest accomplishments of 2oth and 21st century public health. Their efficacy in combating, and in some cases eradicating, deadly diseases is unquestionable and obvious to all but the most dedicated nay-sayers. Epidemiological studies have found that side effects are minimal and well below the effects of the disease themselves. Still there are those who call for “double blind, randomised, placebo controlled, crossover trials” to settle the issue.

While this may sound reasonable to some, there are several factors to consider. The following is by no means a comprehensive list.

The prior probability of efficacy: Vaccines have proven that for some diseases such as smallpox, eradication on a worldwide scale is possible. It has been known since the late 18th century that vaccination against smallpox was possible, and the WHO declared eradication in 1979. Polio has been eliminated in many countries around the world, with only a few areas, mostly those where violence makes programs difficult, where the disease still exists. Similar, although less dramatic results have been found with many other communicable diseases.

The ethics of such a study: Based upon the above, any study that denies some study participants of a proven preventative treatment would be entirely unethical. An example would be withholding insulin from Type 1 diabetics. Based upon prior information, any study would need to compare a new treatment against the existing standard of care.

Existence of existing vaccine: The ethical requirements of such a placebo based study may be met where there is no existing vaccine. In fact, this is often done either in those instances or when a vaccine is introduced into an entirely new population.

Resistance to vaccinations, particularly those that are included in public health programs, is based entirely upon unfounded belief. All research that has been conducted has demonstrated both the efficacy and safety of vaccines as prevention of numerous diseses. It is highly unlikely that any amount of research would alter these beliefs in those who already convinced.

Berating and belittling opponents of vaccinations has not proven effective, and I know that I am guilty of both. However, I do see such campaigns as a danger to public and personal health, and by times, I cannot curtail my anger. Gentler approaches such as the paper on parachutes may be more effective, I don’t know. In the end, education may prevent an increase in the spread of mis-information, and that requires a long term effort that must begin in our schools where students need to be taught both critical thinking skills and the dangers of hyper-skepticism.

This article would be almost be re-written by simply replacing ‘vaccine’ with ‘homoeopathy’, ‘reiki’, ‘acupuncture’, ‘chiropractic’, or any number of energy based pseudo-scientific treatments.

Do parachutes work? Do vaccines work? Do we need placebo based studies on everything?

From David Ng via Boingboing.


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