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Alcohol increases risk of a bicycle crash

Summary: Alcohol + Bicycle = Risk!

A study published by a team of researchers at Johns Hopkins summarizes the results of a survey of 466 Maryland bicyclist fatalities, estimating that a third of them had high blood alcohol levels at the time of their crash.

The report was issued in the February 21, 2001 issue of the Journal of the American Medical Association.

Only five per cent of the fatalities had a helmet on, so there was an elevated chance of death if a crash did occur. It should not be a surprise that people who ride while intoxicated often do not wear helmets.

Blood alcohol levels were estimated from medical records, visits to crash sites and testing of 342 passing bicyclists for breath alcohol. At the .08 grams/deciliter level, legally drunk in most states, the odds of a fatal or serious injury rose by 2,000 per cent. The risk rose as alcohol rose, beginning at a 600 per cent increase if the blood level was only .02 grams/deciliter, equivalent to one drink. The .08 level is typically associated with four to five drinks.

The study found that 30 per cent of the riders who had high alcohol levels also had a history of driving while intoxicated. Some were using bicycles because their driver's license had been suspended or revoked.

The study did not include nighttime injuries and fatalities. If it had the authors believe it might have resulted in an even greater correlation between inebriation and death or injury. They note that riding a bicycle requires more physical coordination than driving a car.

Child bicycle fatalities have fallen by 70 per cent since 1975 even as adult fatalities have increased by about 65 per cent during the same period. The authors recommend that helmet laws be extended to cover adults.

The study's lead author was Guohua Li, MD, Dr.PH. Other authors included John E. Smialek, MD, Susan P. Baker, MPH, and Carl A. Soderstrom, MD. It is now available online for a fee.