A prospective cohort study on minor accidents involving commuter cyclists in Belgium.

The purpose of this study is to gain insight into bicycle accidents. Bicycle accident data and weekly exposure data were prospectively collected for one year to calculate the incidence rate (IR) of bicycle accidents. An accident was included if it occurred during utilitarian cycling, resulting in an acute injury with corporal damage. If an accident occurred, a detailed questionnaire was filled out to collect detailed information about its circumstances and consequences. A sample of 1087 regular (≥2 cycling trips to work a week) adult (40±10 years) cyclists was analyzed. Over the 1-year follow-up period, 20,107 weeks were covered, accumulating 1,474,978 cycled kilometers. Sixty-two participants were involved in 70 bicycle accidents, of which 68 were classified as 'minor'. The overall IR for the 70 accidents was 0.324 per 1000 trips (95% CI 0.248-0.400), 0.896 per 1000 h (95% CI 0.686-1.106) and 0.047 per 1000 km (95% CI 0.036-0.059) of exposure. Brussels-capital region is the region with the highest IR (0.086; 95% CI 0.054-0.118), with a significantly (P<0.05) higher IR compared to Flanders (0.037; 95% CI 0.025-0.050). Injuries were mainly caused by 'slipping' (35%) or 'collision with a car' (19%). The accidents caused abrasions (42%) and bruises (27%) to the lower (45%) and upper limbs (41%). Police, hospital emergency department or insurance companies were involved in only 7%, 10% and 30% of the cases, respectively. It is noteworthy that 37% of the participants indicated that they could have avoided the accident. In order to decrease the number of accidents, measures should be taken to keep cycling surfaces clean and decrease the number of obstacles on bicycle infrastructure. Roads and intersections need to be built so that the collisions between cars and bicycles are decreased to a minimum. Car drivers and cyclists should pay more attention towards each other. Underreporting of minor bicycle accidents in Belgium is confirmed, and is higher than expected. Reliable accident statistics, taking into account exposure, are needed to decide which road safety measures are the most effective. The 'safety in numbers' principle is also applicable for minor bicycle accidents.