Effect of Remediating Blighted Vacant Land on Shootings: A Citywide Cluster Randomized Trial.

Abstract

<i>Objectives.</i> To determine if remediating blighted vacant urban land reduced firearm shooting incidents resulting in injury or death.<i>Methods.</i> We conducted a cluster randomized controlled trial in which we assigned 541 randomly selected vacant lots in Philadelphia, Pennsylvania, to 110 geographically contiguous clusters and randomly assigned these clusters to a greening intervention, a less-intensive mowing and trash cleanup intervention, or a no-intervention control condition. The random assignment to the trial occurred in April and June 2013 and lasted until March 2015. In a difference-in-differences analysis, we assessed whether the 2 treatment conditions relative to the control condition reduced firearm shootings around vacant lots.<i>Results.</i> During the trial, both the greening intervention, -6.8% (95% confidence interval [CI] = -10.6%, -2.7%), and the mowing and trash cleanup intervention, -9.2% (95% CI = -13.2%, -4.8%), significantly reduced shootings. There was no evidence that the interventions displaced shootings into adjacent areas.<i>Conclusions.</i> Remediating vacant land with inexpensive, scalable methods, including greening or minimal mowing and trash cleanup, significantly reduced shootings that result in serious injury or death.<i>Public Health Implications.</i> Cities should experiment with place-based interventions to develop effective firearm violence-reduction strategies.<i>Trial Registration.</i> This trial was registered with the International Standard Randomized Controlled Trial Number (study ID ISRCTN92582209; http://www.isrctn.com/ISRCTN92582209).