Prospective Evaluation of California's Armed and Prohibited Persons System

Statement of the Problem: Firearm violence is a significant public safety and public health problem, and too little is known about the effectiveness of efforts to prevent it. Our purpose is to conduct a rigorous evaluation of California's Armed and Prohibited Persons System (APPS). APPS seeks to recover firearms from individuals who purchased them legally in the past but have recently become prohibited personsunable legally to possess firearmsfollowing a conviction for a serious crime or other event suggesting a high risk for future violence to others or themselves. APPS is a theory-based intervention that may have a significant impact on risk for future violence among members of its target population.
Subjects: Approximately 20,000 individuals eligible for the APPS intervention in 1,041 communities.
Research Design and Methods: APPS is being implemented statewide following a schedule that gives each community an equal opportunity for implementation by using randomization at the community level, with stratification by region, population, and violent crime rate. The subjects of the study are APPS-eligible individuals hierarchically nested within those communities. The principal outcome measure is the incidence of arrest for a firearm-related or violent crime following intervention, comparing individuals in communities that have received the APPS intervention with individuals in communities that have not yet received the intervention.
Analysis: Primary analysis will be on an intent-to-treat basis. Analyses will focus on time to event, using proportional hazards regression, adjusted for the clustered nature of the data and incorporating many individual- and community-level characteristics. Time-varying covariates will be employed where needed. Supplemental analyses on an as treated basis will assess whether the magnitude of the effect is related to the intensity of the intervention at the individual level. To assess the validity of the primary analysis, we will employ multiple ancillary methods, assess multiple pre-specified outcomes, and examine effects on pre-specified subgroups. We will conduct a cost-benefit analysis.
Products, Reports, and Data Archiving: Results will be made available in a final report and in a series of publications in peer-reviewed scholarly journals and will be disseminated to broader audiences in suitable formats. Data and documentation will be archived for future use.
ca/ncf