Use Your Loaf: Poor Quality Discussion Over Bike Helmet Legislation

Today during my drive home, I heard Professor Chris Rissel of the University of Sydney's School of Public Health giving an interview on ABC Radio. 

Professor Rissel said that he had been conducting research into whether legislation that requires cyclists in Australia to wear helmets is beneficial to public health. He said that there is evidence to suggest that the reduction in fatalities and brain damage achieved by the legislation is outweighed by its contribution to other health issues relating to obesity, through the decline in the rate of bicycle usage in the Australian population.
Yesterday, according to The Drum he cited statistics indicating that the number had of bicycles had grown only 21 percent between 1986 and 2006; a period in which the Australian population grew by 58 percent. In his radio interview today, he said there were many studies internationally citing Australia as an example of "what not to do to encourage cycling." 

The interview was followed by another interview with a Professor of Medicine, who was asked to give a detailed description of the kinds of brain injuries that can take place during bicycle crashes. This he did, in rather graphic detail.

Many radio listeners called after that and gave descriptions of injuries they had sustained themselves and stories of how bicycle helmets had saved their lives. The only slight interruption to this narrative of 'helmet as savior' and 'bare headed rider as irresponsible' was a single caller who described how he survived a bare headed bicycle crash into the back of a car and was told afterwards by a surgeon that had he been wearing a helmet he would have certainly been either dead or paralysed, based on some form of wedge effect that may or may not be applicable to other such cases.

There was no discussion of the public bicycle stations around Melbourne, the possible nature of a relationship between the helmet requirement and rates of usage, the actual rates of bicycle related head trauma and other conditions or changes therein since the introduction of helmet legislation. 

Now my aim here isn't to argue either way. All I would like to point out is that the outcome of the discussion occurred, whether right or wrong, had far more to do with the rules of newsworthiness than it did with any actual understanding of the research that had been conducted. How so? I shall endeavor to explain. 

Imagine for a moment that Professor Rissel's interview had been followed by an interview with a heart surgeon and the journalist (in this case it w as Libbi Gorr, but let us not blame her for the nature of her occupation) had asked him to describe, in graphic detail, the effects of various heart conditions upon a person't well being and the gradual process of one's internal organs being overwhelmed and choked with fat until they are no longer able to function and we die. Imagine then, if a number of people suffering from obesity were to have called and given testament to the debilitating effects of their condition and their constant fear of death through heart failure or diabetes. After all, as a report later in the evening pointed out, one in four Australians are obese and those are two of the most common health risks to the population, with numbers vastly greater than the incidence of those particular cycling related head injuries that could have been survived through the use of a helmet. Would that have left listeners feeling rather differently about it all? Might the percentage of listeners who spent this evening thinking 'well, perhaps professor Rissel may have had a point' have been somewhat larger?

Maybe, maybe not. After all, people do have other means of forming views on such matters. What is very clear is that we are far, far less likely to hear the kind of radio broadcast I just described than we are to hear shows that run something like Libbi Gorr's effort. Slow and gradual processes cannot compete for news worthiness with the immediacy and impact (if you'll excuse the unfortunate pun) of a head hitting a hard surface. Complex social relationships with multiple causes have no chance against the obvious causality of a simple, blow by blow description of a physical event. A disease is relatively shrouded in mystery when compared to physical trauma. This means that inevitably public sentiment must be distorted. It means that a first hand description of an evocative but statistically inferior (perhaps statistically inferior: Professor Rissel didn't get a chance to tell us whether or not he was able to identify a statistical correlation between helmet legislation and obesity) can influence what we think more than the presumably careful and meticulous work of a researcher over several years. Professor Rissel has been looking into the matter at least since 2010 which is the date given on his public profile for 'Safer cycling: A partnership project to better understand cycling patterns, hazards and incidents' and probably for longer. Though it is right that journalists should question what he is saying and compare it to other sources, the treatment that actually eventuated in this case, and in many such cases where the complex seeks to be heard amid the chorus of simplicity that dominates mainstream media (even the ABC) was dismissive and misleading. 

Prof. Rissel's profile on the University website can be viewed here:http://sydney.edu.au/medicine/people/academics/profiles/crissel.php

A relevant ABC article can be viewed here:
http://www.abc.net.au/news/2012-07-11/phillips-cycling-boom/4122046

Please consider supporting my blog by clicking the advertisements.

Helicobacter Pylori and Ulcers

I was having an interesting discussion with a microbiology student this morning about ulcers. This is how she explained them to me.

We all have helicobactor pylori in our stomachs. It is the bacterium known to cause stomach ulcers. It also causes ulcers in the duodenum. For some reason, people who get one type of ulcer do not get the other.

Getting stomach ulcers is a risk factor for stomach cancer.

It is not yet understood exactly why some people get ulcers and some don't. The mechanism by which they occur is understood as follows:

The helicobactor pylori rely on stomach acid to activate the enzyme 'urease' which they need in order to digest urea. However, to digest the urea they need an acid free environment. To achieve this, they physically burrow into the mucosa, which is the epithelial lining of the stomach. They use their flagella to propel themselves. The mucosa protects the stomach from it's acidic contents. It is the physical damage caused to it by the burrowing helicobactor pylori that allows the acid to get through this protective layer and cause harm to other tissues, thus causing an ulcer.

That is her explanation as I understood it and I'm pretty sure that it's a well accepted one based on her university textbooks, so  I have no reason to question it, but please comment if you know anything further or if I have misunderstood.

Traditionally people have associated ulcers with stress. In the past, doctors have even advised patients with ulcers to avoid stress. The problem with this is that there is no known correlation between stress and either the thickness of the mucosa or the concentration of helicobactor pylori. This means that stress is unlikely to actually be a contributing factor.

Perhaps there is a competitive relationship between Helicobactor pylori and other microbes that inhabit the stomach. That was the first though that occurred to me. Or perhaps the body's ability to regulate the thickness of the mucosa could be impaired somehow, perhaps, for example, through some form of deficiency? Further research will no doubt be required before ulcers can be fully understood and treated.

Another Climate Change 'Debate'

"Never argue with a fool; onlookers may not be able to tell the difference." Author Unknown.

 Some farmers newspaper is having a go at a university for not wanting to host a debate between the two 'sides' of the climate change issue. So what? Probably nobody would notice. However, Andrew Bolt has added it to his blog, which is connected to a mass tabloid. Unfortunately, there are a larger number of Herald Sun readers in Australia than there are kangaroos. 

These people's main argument seems to be that the two scientists they invited to represent them should be considered credible on the basis of their previous work experience and qualifications. Actually having something intelligent to say or having published credible evidence that has been examined by peers and found to conform with the scientific method doesn't seem to rate very highly among their criteria. 

Of course, debating a climate change denier would be something like trying to have a reasoned discussion with a concrete wall: no matter what you say, the rude symbols someone painted there aren't going to change their message. It would be insulting to the academic community to ask them to participate in that kind of freak show. Universities are places of learning, not puppets in these people's sick political games. 

Debate is pointless when one side doesn't have a point other than it's own short term interests and refuses to listen to the other. Proper scientific debate, anyway, needs to be done on paper, not on a stage. In trying to reduce carefully recorded data, calculations and mapping to the form of 'facts n' figures' that can be slung across a room in the form of rhetoric, the vast majority of their meaning and value is inevitably lost.