Interrupted Time Series Analysis of Bar/Tavern Closing Hours and Violent Crime.

Importance: It is well established that alcohol outlets (ie, places that sell alcohol) attract crime, particularly during late-night hours.
Objective: To evaluate the association of Maryland Senate Bill 571 (SB571), which reduced the hours of sale for bars/taverns in 1 Baltimore neighborhood from 6 am to 2 am to 9 am to 10 pm, with violent crime within that neighborhood.
Design, Setting, and Participants: This controlled interrupted time series analysis compared the change in violent crime density within an 800-ft buffer around bars/taverns in the treatment neighborhood (ie, subject to SB571) and 2 control areas with a similar mean baseline crime rate, alcohol outlet density, and neighborhood disadvantage score in the City of Baltimore between May 1, 2018, and December 31, 2022. The interrupted time series using Poisson regression with overdispersion adjustment tested whether the violent crime density differed before vs after the policy change in the treatment neighborhood and whether this difference was localized to the treatment neighborhood.
Exposure: Statutory reduction of bar/tavern selling hours from 20 to 13 hours per day in the treatment neighborhood.
Main Outcomes and Measures: The primary outcome was all violent crime, including homicide, robbery, aggravated and common assault, and forcible rape. Secondary outcomes were homicides and assaults. All violent crime measures summed the monthly incidents within 800 ft of bars/taverns from 8 pm to 4 am. For each outcome, a level change estimated the immediate change (first month after implementation), and a slope change estimated the sustained change after implementation (percent reduction after the first month). These level and slope changes were then compared between the treatment and control neighborhoods.
Results: The treatment neighborhood included 26 bars/taverns (mean [SD] population, 524.6 [234.6] residents), and the control neighborhoods included 41 bars/taverns (mean [SD] population per census block, 570.4 [217.4] residents). There was no immediate level change in density of all violent crimes the month after implementation of SB571; however, compared with the control neighborhoods, the slope of all violent crime density decreased by 23% per year in the treatment neighborhood after SB571 implementation (annualized incidence rate ratio, 0.77; 95% CI, 0.60-0.98; P = .04). Similar results were seen for homicides and assaults. Several sensitivity analyses supported the robustness of these results.
Conclusions and Relevance: This study's findings suggest that alcohol policies that reduce hours of sale could be associated with a reduction in violent crimes. Given these findings, SB571 may serve as a model for other cities looking to create safer neighborhoods.