title: Pediatric bicycle-related head injuries: a population-based study in a county without a helmet law.
abstract: BACKGROUND
  Head injuries are the leading cause of death among cyclists, 85 % of which can be prevented by wearing a bicycle helmet. This study aims to estimate the incidence of pediatric bicycle-related injuries in Olmsted County and assess differences in injuries between those wearing helmets vs. not.
  
  
  METHODS
  Olmsted County, Minnesota residents 5 to 18 years of age with a diagnostic code consistent with an injury associated with the use of a bicycle between January 1, 2002, and December 31, 2011, were identified. Incidence rates were calculated and standardized to the age and sex distribution of the 2000 US white population. Type of injuries, the percentage requiring head CT or X-ray, and hospitalization were compared using a chi-square test. Pediatric intensive care unit (PICU) admission, permanent neurologic injury, seizure, need for mechanical ventilation, and mortality were compared using Fisher's exact test.
  
  
  RESULTS
  A total of 1189 bicycle injuries were identified. The overall age-adjusted incidence rate of all injuries was 278 (95 % CI, 249 to 306) per 100,000 person-years for females and 589 (95 % CI, 549 to 629) for males. The corresponding rates for head injuries were 104 (95 % CI, 87 to 121) for females and 255 (95 % CI, 229 to 281) for males. Of patients with head injuries, 17.4 % were documented to have been wearing a helmet, 44.8 % were documented as not wearing a helmet, and 37.8 % had no helmet use documentation. Patients with a head injury who were documented as not wearing a helmet were significantly more likely to undergo imaging of the head (32.1 percent vs. 11.5 %; p < 0.001) and to experience a brain injury (28.1 vs. 13.8 %; p = 0.008).
  
  
  CONCLUSIONS
  Children and adolescents continue to ride bicycles without wearing helmets, resulting in severe head and facial injuries and mortality.
authors.affiliation: Mayo Clinic Children's Center, 200 First Street SW, Mayo 16E, Rochester, MN, 55905, USA. drruchikaushik@yahoo.com.
authors.forename: Ruchi
authors.initials: R
authors.lastname: Kaushik
authors.affiliation: Mayo Clinic Children's Center, 200 First Street SW, Mayo 16E, Rochester, MN, 55905, USA.
authors.forename: Isabelle M
authors.initials: IM
authors.lastname: Krisch
authors.affiliation: Mayo Clinic Children's Center, 200 First Street SW, Mayo 16E, Rochester, MN, 55905, USA.
authors.forename: Darrell R
authors.initials: DR
authors.lastname: Schroeder
authors.affiliation: Mayo Clinic Children's Center, 200 First Street SW, Mayo 16E, Rochester, MN, 55905, USA.
authors.forename: Randall
authors.initials: R
authors.lastname: Flick
authors.affiliation: Mayo Clinic Children's Center, 200 First Street SW, Mayo 16E, Rochester, MN, 55905, USA.
authors.forename: Michael E
authors.initials: ME
authors.lastname: Nemergut
keywords: Bicycle helmets; Head injuries; Public health