title: The impact of small changes in bar closing hours on violence. The Norwegian experience from 18 cities.
abstract: OBJECTIVE
  To estimate the effect on violence of small changes in closing hours for on-premise alcohol sales, and to assess whether a possible effect is symmetrical.
  
  
  METHODS
  A quasi-experimental design drawing on data from 18 Norwegian cities that have changed (extended or restricted) the closing hours for on-premise alcohol sales. All changes were ≤ 2 hours.
  
  
  METHODS
  Closing hours were measured in terms of the latest permitted hour of on-premise trading, ranging from 1 a.m. to 3 a.m. The outcome measure comprised police-reported assaults that occurred in the city centre between 10 p.m. and 5 a.m. at weekends. Assaults outside the city centre during the same time window should not be affected by changes in closing hours but function as a proxy for potential confounders, and was thus included as a control variable. The data spanned the period Q1 2000-Q3 2010, yielding 774 observations.
  
  
  RESULTS
  Outcomes from main analyses suggested that each 1-hour extension of closing hours was associated with a statistically significant increase of 4.8 assaults (95% CI 2.60, 6.99) per 100,000 inhabitants per quarter (i.e. an increase of about 16%). Findings indicate that the effect is symmetrical. These findings were consistent across three different modelling techniques.
  
  
  CONCLUSIONS
  In Norway, each additional 1-hour extension to the opening times of premises selling alcohol is associated with a 16% increase in violent crime.
authors: Norwegian Institute for Alcohol and Drug Research, Oslo, Norway. ir@sirus.no
authors: Ingeborg
authors: I
authors: Rossow
authors: Thor
authors: T
authors: Norström
mesh_terms: D000428:Alcohol Drinking / Q000453:epidemiology / Q000331:legislation & jurisprudence*; D000434:Alcoholic Beverages / Q000600:supply & distribution; D002947:Cities; D003132:Commerce / Q000331:legislation & jurisprudence; D003430:Cross-Sectional Studies; D006291:Health Policy; D006801:Humans; D009664:Norway / Q000453:epidemiology; D011633:Public Facilities / Q000331:legislation & jurisprudence*; D013997:Time Factors; D014754:Violence / Q000331:legislation & jurisprudence / Q000517:prevention & control* / Q000706:statistics & numerical data