Do Not Let This Headline Scare You!

Last month Reuters reported on a study of bicycle injuries that found an increase in serious bicycling injuries in a Denver hospital from 1996 to 2006. The report, which carried the headline “Bicycle injuries in U.S. becoming more severe,” has been widely picked up, circulated, and worried over. Now it’s time to put the genie back in the bottle.

The study itself is not available – it was presented at the American College of Surgeons’ 95th annual Clinical Congress in Chicago – so we are left to interpret the Reuters article and a news release from the University of Colorado.

From Reuters:

The severity of injuries and time spent hospitalized for bicycle injuries tended to increase in the past decade, according to the findings…The number of chest injuries rose by 15 percent, while abdominal injuries increased threefold over the last five years.

It may well be true that bicycling injuries are becoming more severe, but before we jump to too many conclusions about what this means, there is a lot more we need to know. From what we already know, however, it is clear that the reporting on these findings has been overblown and sometimes plainly inaccurate.

The first obvious point to make is the limited scope of the study – 329 bicycling injuries in one Denver hospital between 1996 and 2006 – hardly justifies the headline’s claim that the study says anything about what is happening in the entire U.S. How much can we generalize about the findings from the Rocky Mountain Regional Trauma Center in Denver? The author of the study, Jeffry Kashuk, made this point in the University of Colorado release saying, “These results were stunning but we must remember that this is only a single center study. Our findings and data need to be verified by a larger, multi-centered national study.”

It is not actually clear how stunning the results are. According to the University of Colorado release, one of the researchers plotted the locations of the crashes on a Denver map, and noticed that the “major concentration of collisions took place in the downtown urban areas and the majority of riders were older males, suggesting a greater frequency of urban commuters opposed to recreational riders.”

Reuter’s continues:

The rise in injury severity likely reflects an increased rate of “motor vehicle associated injuries, which might suggest, along with a trend toward older age, that the injuries occurred in commuters more frequently than the past, as opposed to recreational riders,” Kashuk said.

He is saying that injuries are more severe when a bicyclist crashes with a car than in other types of bicycle crashes. He is not saying that there is a greater risk of crashing with a car than before. He is also not saying that car-crash injuries are getting more severe. It appears that the study did not control for the type of riding that led to the injuries, focusing instead on the change in injury severity over time. He is saying that as people ride in traffic more, there will be more “motor vehicle associated injuries.”

We know from the U.S. Census Bureau that the percentage of bicycle commuters in Denver increased 93% just between 2000 and 2006. Thus an increase in the types of injuries more associated with commuting is not surprising.

The study is not saying that bicycle commuting is becoming more dangerous – just that more people are doing it and therefore there are more serious injuries in one Denver hospital. That makes headlines like this one from Denver’s ABC affiliate – “Injuries To Cyclists Who Commute Becoming More Severe” – inaccurate and misleading. The injuries may be more severe, but the study doesn’t appear to claim that commuter injuries are becoming more severe.

The author of the report rightly calls for more safe accommodation of cyclists to avoid these injuries. And he is certainly correct that “There is a paucity of studies looking specifically at bicycle injuries”.

Headlines like the ones being attached to the Denver study may deter some people from riding. That would actually have a negative impact on the safety for the rest of us. Peter Jacobson’s famous study “Safety in Numbers” showed that as more people ride, drivers become more aware of cyclists, making everyone safer: “The likelihood that a given person walking or bicycling will be struck by a motorist varies inversely with the amount of walking or bicycling.”

Researchers John Pucher, Jennifer Dill, and Susan Handy recently published a review of the literature on bicycling, “Infrastructure, Programs, and Policies to Increase Bicycling: An International Review”. They conclude: “The combined evidence presented in these studies indicates that the health benefits of bicycling far exceed the health risks from traffic injuries, contradicting the widespread misperception that bicycling is a dangerous activity.”

So do not let any scary headlines make you think that bicycling is becoming more dangerous. There certainly are risks, and education, proper care and investment from communities all over the country are extremely important. The good news is that the more of us out three riding, the safer – and healthier – we’ll all be.

UPDATE: The author of the study, Jeffry Kashuk, was kind enough to speak with me. He mentioned that the name of the presentation and upcoming study is Increased Popularity of Urban Bicycle Transportation in America: The Perfect Storm for an Injury Epidemic.

He summarized his argument in this way:

a. There are more bicycle commuters today

b. Bicycle commuters appear to be at risk for more severe injuries than trail-only, recreational cyclists

c. Too many urban areas, like Denver, are encouraging bicycle commuting without investing in the needed facilities to keep them safe

The result, he says, will be an epidemic of injuries to bike commuters.

He makes a perfectly legitimate point, as far as it goes. From the point of view of promoting safe cycling, there is a bit of a chicken and egg question here. Cities won’t invest in safe infrastructure if very few people ride, and people won’t ride if all they hear is about how dangerous cycling is. In my view, both promotion and safe facilities are necessary to encourage safe cycling.  Again, Dr. Kashuk is right to call for more safe facilities, but not to call for a halt to cities’ promotion efforts. We can and should do both.

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