A 10-year incidence of acute whiplash injuries after road traffic crashes in a defined population in Northern Sweden

Objective To examine the annual incidence of acute whiplash injuries after road traffic crashes in a geographic catchment area in Northern Sweden during the period 2000-2009. Design Descriptive epidemiology determined by prospectively collected data from a defined population. Setting The study was conducted at a public hospital in Sweden. Participants The population of the hospital's catchment area (136,600 inhabitants in 1999 and 144,500 in 2009). Methods At the emergency department, all injured persons (approximately 11,000 per year) were asked to answer a questionnaire about the injury incident. Data from the medical records also were analyzed. From 2000-2009, 15,506 persons were injured in vehicle crashes. Persons who were subject to an acute neck injury within whiplash-associated disorder grades 1-3 were included. The overall and annual incidences were calculated as incidence. Age, gender, type of injury event, and direction of impact were described. The incidences were compared with national statistics on insurance claims from 2003, 2007, and 2008 to detect changes in the proportions of claims. Main Outcome Measures The annual incidence of acute whiplash injuries. Secondary outcome measures were types of injury events, age and gender distribution, changes in the proportion of rear-end crashes during 2000-2009, and changes in the proportion of insurance claims during 2003-2008. Results During 2000-2009, 3297 cases of acute whiplash injury were encountered. The overall incidence was 235/100,000/year. The average yearly increase in incidence was 1.0%. Women comprised 51.9% and men 48.1% of the injured. Car occupants (86.4%) and bicycle riders (6.1%) were most frequently injured. The proportion of rear-end crashes decreased from 55% to 45% from 2000-2009. The proportion of insurance claims significantly decreased between 2003 and 2008 (P < .0001, χ2 test). Conclusion The incidence of emergency department visits attributable to acute whiplash injuries after road traffic crashes have been relatively stable during the past decade in our area, except in 2007 and 2008, when a peak occurred