Risk factors that lead to bicycling injuries in city traffic

In a preliminary analysis of 143 bicyclists injured in traffic crashes, the researchers aimed to identify contributing risk factors. "The most interesting things are the number of cyclists who have alcohol in their system, and the number of cyclists who wear helmets is unbelievably low," according to principal investigator Spiros Frangos, MD, MPH, FACS.

This study, commissioned by the State of New York, is unique in that it looks at injuries bicyclists sustain in motor vehicle crashes, Dr. Frangos said. "A lot of what's been done in this realm by city and state agencies has more to do with bicyclists' mortality in motor vehicle crashes," he said. "If you look just at mortalities, you're looking at less than one percent of these incidents." Added coinvestigator Patricia Ayoung-Chee, MD, "We're looking at morbidity, hospitalization, and the need for rehabilitation, which is all information that we can then use to determine how this affects the health care system overall."

The investigators reported on preliminary results from the first year of a three-year study. The completed study will also include data on pedestrians struck by vehicles, Dr. Frangos said. The first phase of data analysis identified these risk factors among injured cyclists: 87 percent were men and 96 percent were over age 18; 13 percent were intoxicated; five percent were listening to music.

Despite helmet laws, only 24 percent of the injured bicyclists were wearing helmets. New York State law requires all cyclists 13 and younger to wear helmets, and New York City mandates helmets on all working cyclists -- the latter typified by the bicycle delivery persons weaving through Midtown traffic. Forty-one percent of the study subjects sustained injuries on the job, but only about one-third of those working cyclists (32 percent) were wearing helmets.

"I don't think the New York City laws are being enforced," Dr. Frangos said.

The study also looked at the nature of bicycle-motor vehicle accidents. Eighteen percent of the injured cyclists were using a bike lane and 17 percent collided with a vehicle door. Seventeen percent of the incidents were hit-and-run. Taxi cabs accounted for 35 percent of bicyclists' injuries.

The investigators have been sharing their data with the state and city departments of transportation and health as well as the New York Police Department. They are also seeking a state grant that would have practitioners speak to community groups to reinforce bicycle safety measures and prevent further traumatic injuries to bicyclists.

Coauthors with Drs. Frangos and Ayoung-Chee are George Foltin, MD; Ronald J. Simon, MD, FACS; Deborah Levine, MD; Omar Bholat, MD, FACS; Dekeya Slaughter-Larkem; Steven S. Schumacher, MD, FACS; and H. Leon Pachter, MD, FACS.