Abstract
Background: During the spring of 2007, the police reported a marked increase in violence and binge drinking related to high school student graduation parties on weekday nights at restaurants in Stockholm city. This spurred a multi-component community intervention project to reduce these problems. Aims: This study aims to evaluate the impact of the intervention on youth-related violence on weekday nights in 2008-2010. Design and Method: The outcome measure entailed the number of violence-related emergency room visits on weekday nights (10:00 pm-6:00 am) by adolescents aged 18-20 years. The study period was 1 April-31 May, which is when most student graduation parties took place. The data covered the years 2005-2010, with three data points before the intervention, and three after the intervention was introduced. Because the intervention was expected to apply to weekdays only, the control series involved a corresponding indicator pertaining to weekend nights (10:00 pm-6:00 am). The intervention effect was assessed by means of difference-in-differences estimation. Results: The estimated intervention effect according to the difference-in-differences estimation models was a statistically significant 23% reduction of violence among young people. Discussion and Conclusion: This type of intervention is a promising measure of preventing youth violence and deserves to be continued. Such continuation would also provide additional data required for a more conclusive assessment.