Category Archives: Bike Riding/Helmets

Urban Cycling, Part 2: Hit and Run Drivers and Bike Helmets

A doctor colleague of the skeptical cardiologist was riding his bike on a quiet road here in St. Louis recently when he suddenly awoke in a hospital bed. His friend who was riding in front of him heard a crash, turned and saw a black car making a U-turn and speeding off. Fortunately, the good doctor, suffered only the concussion and multiple bruised ribs and will live to ride again

He is in his seventies and I asked him if he would, indeed, climb onto the saddle of a two-wheeled vehicle in the future and he indicated yes, but never again on roads shared with cars.

I also inquired as to the state of his bike helmet post-trauma: it was shattered into multiple pieces.

In a previous post I pondered the question: Does cycling to work make you more or less likely to die?

cycling to work for many individuals would provide the daily physical activity that is recommended for cardiovascular benefits. However, cycling in general, and urban cycling in particular, carries a significant risk of trauma and death from accidents and possibly greater exposure to urban pollutants.

In the Netherlands cycling to work likely makes you less likely to die.

One study quantified the impact on all-cause mortality if 500,000  people made a  transition from car to bicycle for short trips on a daily basis in the Netherlands and concluded

For individuals who shift from car to bicycle, we estimated that beneficial effects of increased physical activity are substantially larger (3–14 months gained) than the potential mortality effect of increased inhaled air pollution doses (0.8–40 days lost) and the increase in traffic accidents (5–9 days lost). Societal benefits are even larger because of a modest reduction in air pollution and greenhouse gas emissions and traffic accidents.

In St. Louis, however, I suspect my longevity would be substantially reduced by cycling the 15 miles of heavily trafficked roads from University City to St. Lukes Hospital in Chesterfield. I would be cheek to jowl with SUVs, pick-up trucks, and mini-vans full of distracted, texting and chatting commuters.

Should  Bike Helmets Be Mandated?

Like most people I know, my colleague wears a bike helmet religiously when cycling. He, like many who have shared their bike accident stories with me, believes the bike helmet saved his life. I certainly can’t refute that possibility but it is impossible to know with certainty.

I’ve posted my analysis of the wisdom of mandating bike helmets here and even after hearing the good doctor’s story,  I still refuse to wear one.

Typical skeptical cardiologist bike riding garb. No helmet but safari (not bee-keeper) hat because sun is not his facial friend.

A commonly cited statistic is that bike helmets reduce serious head injuries by 85% and brain injuries by 88%.  This comes from an observational  study  published in 1989 which has serious limitations and has never been reproduced. For an exhaustive critique of these data see here.

I think a fair summary is in this British Medical Journal editorial which is behind a paywall but can be reviewed as a PDF here (bmj-june-2013.pdfbicycle helmets and the law).

 

Larry Husten, a journalist, who writes an excellent cardiology blog at cardiobrief.org apparently agrees with me and has recently written about “The Unintended Consequences of Bike Helmets.”

I encourage everyone to read his post which can be found here.

Here is his main point:

I am opposed to public health campaigns that focus on helmets, thereby implanting in people’s minds the dangers of cycling. Instead, in my view, the public health agenda regarding cycling should be to promote the far greater health benefits of cycling. The overarching goal of any public health campaign should be to dramatically increase cycling in the US, thereby encouraging physical activity and helping to reduce obesity and diabetes.  In tiny Denmark, by way of example, one expert, Lars Bo Andersen, PhD, of Western Copenhagen University of Applied Sciences, reports that “26 persons were killed in the whole country in cycle accidents last year, but more than 6000 deaths were avoided due to the huge amount of physical activity this behavior is a result of.”

Circuitously Yours,

-ACP

Speaking of Holland, the skeptical cardiologist will be visiting this hotbed of cycling, tulips and dikes in July.

I’ll be staying in Haarlem but wandering around the country researching cycling, assisted suicide and the Dutch dairy industry which may be responsible for the Dutch having gone from being among the shortest people in Europe to being the tallest in the world.

Is Not Wearing A Bike Helmet As Stupid As Smoking Cigarettes?

IMG_4261
The “Route” from my house to the great urban park, Forest Park, around and back. Sans incursions into the dangerous paths less traveled

Several weeks after  my cycling misadventures which resulted in non cardiac chest pain, I climbed back in the saddle again and rode the route that had resulted in my calamitous fall.

This time, I avoided the mysterious path less traveled.

As I approached  Washington University an elderly man riding a bike and wearing a bike helmet came up beside me. He was clearly very irritated by the fact that I was not wearing a bike helmet and kept gesticulating at his helmet to indicate that this was the proper choice of head gear.

I had, as is my usual practice, chosen not to wear a helmet  and this man had taken it upon himself to nonverbally lecture me on what he perceived was inappropriate risky behavior.

As I continued my ride I began ruminating on my decision to engage in  bike riding without a helmet and wondering if I was being like my patients who continue to smoke cigarettes despite my warnings of the health consequences of that behavior.

There can only be two reasons for an educated person not to wear a helmet:

1. S/he believes there is no or insufficient evidence that wearing a bike helmet will reduce their risk of serious head injury while riding.

2. S/he accepts that helmet wearing reduces injury but is willing to accept this risk because not wearing the helmet is more pleasurable or convenient.

Similarly, my cigarette smoking patients may either reject the (overwhelming) evidence of the dangers of this behavior or they may believe it is dangerous but feel that smoking is so pleasurable they decide to continue.

Not wearing a bike helmet lacks the addictive element that cigarette smoking contains but otherwise I think it is a reasonable analogy.

Do Bike Helmets Reduce Injury ?

Despite widespread public health advise to wear bike helmets, I have maintained  in previous posts that evidence for bike helmets reducing injury is lacking.

I’ve spent a fair amount of time since this gentleman upbraided me for being helmet-less reviewing the data again. I was prepared to regularly wear one if the data supported it. But it doesn’t.

A commonly cited statistic is that bike helmets reduce serious head injuries by 85% and brain injuries by 88%.  This comes from an observational  study  published in 1989 which has serious limitations and has never been reproduced. For an exhaustive critique of these data see here.

I think a fair summary is in this British Medical Journal editorial which is behind a paywall but can be reviewed as a PDF here (bmj-june-2013.pdfbicycle helmets and the law)

Cowritten by David Spiegelhalter, the Winton professor for the public understanding of risk at the London School of Hygiene, the editorial was commenting on a paper in the same issue which reported that a Canadian mandatory bike helmet law had minimal effect on cycling-related head injuries.

The writers note that this contradicts previous observational studies which have suggested a benefit from helmet wearing.

Like all observational studies, these bike helmet studies are “vulnerable to many methodological shortcomings”:

  1.  If the controls are cyclists presenting with other injuries in the emergency department, then analyses are conditional on having an accident and therefore assume that wearing a helmet does not change the overall accident risk
  2. Observational studies cannot account for confounding variables that are unmeasured. For example, people who choose to wear bike helmets may be more cautious than those who don’t and so less likely to have a serious head injury regardless of wearing a helmet. (A 1997 study found that adolescents who smoked cigarettes were more likely to use smokeless tobacco, have multiple sexual partners, and not use bicycle helmets)

Many states and countries have passed laws mandating helmet wearing but people who are forced by legislation to wear a bike helmet may wear it in a sloppy , ineffective manner. Their behavior may also change   through “risk compensation” wherein they behave more irresponsibly in the believe that they are protected from injury.

A single study has also reported that car drivers give a larger clearance to cyclists without a helmet.

I have concluded that my not wearing a bike helmet is due to lack of evidence to support the health consequences of that behavior. This happens to perfectly align with my disdain for bike helmets which chafe my forehead, make my head sweat and reduce my ability to hear (both charming and lethal) things.

Do Cigarettes Cause Death?

Cigarette smokers, on the other hand, can find no serious scientist or physician who is not convinced of the danger of this lethal habit because the scientific data are overwhelming. The CDC estimates cigarette smoking is responsible for 480,000 deaths per year and that it causes 90% of lung cancers and 80% of chronic obstructive lung disease. The only possible explanation for continuing is the element of addiction combined with the pleasure obtained from smoking.

Public Health Laws: Bike Helmets and Cigarette smoking

Australia and New Zealand are the only countries to have mandatory helmet laws. In the US, according to helmets.org, bike helmets are mandatory in 22 states.

In St. Louis County, they are mandatory for children under the age of 17. In some St. Louis municipalities (Creve Couer for one) they are mandatory for all are groups.

To date, there is no evidence that mandatory bike helmet laws reduce head injuries so why are they being passed?

On the other hand, the dangers of cigarette smoking are clear and there are no countries or states which make it illegal.

To those who would shame we non helmet wearers I say: “Spend your time shaming those who smoke cigarettes”.

By the way, whenever public policy doesn’t seem to correspond to the evidence, we should look for bias and special interests.

It’s obvious in the world of tobacco that the bias and special interest  toward allowing smoking comes from the tobacco industry.

In the cycling world, the bias and influence comes from the manufacturers of bike helmets.

Helmet free and loving it

-ACP