Hitting the Streets: Bike Commuting Injuries in Portland, Oregon

The City of Portland, Oregon has made considerable investments into bicycle infrastructure, and the number of cyclists commuting to work in the metro area continues to increase. While the number of bike crashes appear to decrease annually, limited data exist on the types and incidence of injuries sustained during bike commuting. We conducted prospective surveillance of self-reported injuries in a cohort of 962 adults for a one-year period. A baseline questionnaire and monthly surveys were completed online. Riders commuted by bike an average of 10 days per month, with an average roundtrip distance of 11 miles. A total of 164 riders (18%) reported 192 injury events and 49(5%) reported 50 events in which a physical injury was severe enough to require medical attention ("serious injury"). The most common sites of injury were the legs and arms, and the skin and soft tissue. The annual incidence rate for all injury events was 15.0 per 100,000 miles travelled (95% CI, 13.2-17.5), and for serious injury events was 3.9 per 100,000 miles travelled (95% CI, 2.9-5.1). We failed to demonstrate differences in injury risk by age, gender, safety practices, and commuting experience. However, use of helmets at the time of an injury event was associated with a lower risk of serious injury (unadjusted OR = 0.32, 95% CI 0.12-0.89). Poor roadway conditions and motor vehicles were reported in 20% and 48% of serious injury events, respectively, suggesting that environmental factors could be important contributors to serious injury.