RT Journal Article SR Electronic T1 Using synthetic control methodology to estimate effects of a Cure Violence intervention in Baltimore, Maryland JF Injury Prevention JO Inj Prev FD BMJ Publishing Group Ltd SP 61 OP 67 DO 10.1136/injuryprev-2020-044056 VO 28 IS 1 A1 Shani A Buggs A1 Daniel W Webster A1 Cassandra K Crifasi YR 2022 UL http://injuryprevention.bmj.com/content/28/1/61.abstract AB Objective To estimate the long-term impact of Safe Streets Baltimore, which is based on the Cure Violence outreach and violence interruption model, on firearm violence.Methods We used synthetic control methods to estimate programme effects on homicides and incidents of non-fatal penetrating firearm injury (non-fatal shootings) in neighbourhoods that had Safe Streets’ sites and model-generated counterfactuals. Synthetic control analyses were conducted for each firearm violence outcome in each of the seven areas where Safe Streets was implemented. The study also investigated variation in programme impact over time by generating effect estimates of varying durations for the longest-running programme sites.Results Synthetic control models reduced prediction error relative to regression analyses. Estimates of Safe Streets’ effects on firearm violence varied across intervention sites: some positive, some negative and no effect. Beneficial programme effects on firearm violence reported in prior research were found to have attenuated over time.Conclusions For highly targeted interventions, synthetic control methods may provide more valid estimates of programme impact than panel regression with data from all city neighbourhoods. This research offers new understanding about the effectiveness of the Cure Violence intervention over extended periods of time in seven neighbourhoods. Combined with existing Cure Violence evaluation literature, it also raises questions about contextual and implementation factors that might influence programme outcomes.Census block group-level data are available in a public, open access repository. Data on homicides, non-fatal shootings and arrests were obtained through both the Baltimore City Open Data portal (https://data.baltimorecity.gov/) and the Baltimore Police Department. Police Department data requests must be submitted to the agency.