Modifiable risk factors for youth firearm injury and death include unsafe storage of a firearm in the home, prior victimization/aggression, substance use, and depressive symptoms, yet there are few partnerships with firearm owners and firearm safety training programs to implement effective, non-policy-based preventive interventions for youth firearm injury. This study will conduct a hybrid effectiveness-implementation trial to evaluate the effectiveness of Guardians 4 Health, a bystander intervention designed to promote changes in firearm injury prevention norms, attitudes, intentions, and behaviors among a sample up to 60 4-H Shooting Sports Club communities comprising both adults and youth. This project is designed to build the evidence base for interventions that promote safe behaviors related to youth firearm use and injury prevention and advance firearm injury prevention science by supporting a synergistic partnership between well-established firearm injury, suicide, and violence prevention researchers and the national 4-H Shooting Sports community.

Firearm injury and mortality is a major public health concern for American youth age 1-19. Only motor vehicle crashes kill more American youth than firearms. In 2018 alone, 1729 American youth died from firearm injuries (50% firearm homicide, 42% firearm suicide) and over 6500 youth were treated in an emergency department for firearm injury; these injuries have major long-term consequences for youth and their families. Approximately one-third of American youth live in a home with a firearm. Risk factors for youth firearm injury and death, such as unsafe home storage of a firearm, prior victimization/aggression, substance use, and depressive symptoms, can be modified. Community partnerships are essential for developing and enacting effective change in injury risk factors, particularly for youth. Due to the fraught political landscape and lack of research funding, partnerships with firearm owners and firearm safety training programs to create and disseminate effective, non-policy-based preventive interventions for youth firearm injury are lacking.

Bystander intervention (BI) is an intervention framework rooted in social psychological theories such as the Theory of Planned Behavior (TPB), with proven efficacy and effectiveness targeting both individual and community behavior change. "Guardians 4 Health" is a three-part, already-piloted intervention that uses the BI framework and TPB mechanisms to promote community norms change about firearm safety, BI, and harm reduction techniques (e.g., safe storage, reducing access to lethal means, conflict resolution). Recognizing that BI is most rigorous when led by credible messengers, Guardians 4 Health uses instructional, peer-to-peer, and social-media strategies in conjunction with community organizations that are deeply connected to firearm safety efforts. Pilot data supports Guardian 4 Health's acceptability and feasibility in changing firearm owners' norms and behaviors.

The necessary next step in this intervention development is to evaluate its effectiveness using a randomized, controlled study design. Our community partner, the National 4-H Shooting Sports Program, is a national leader and trusted messenger for firearm safety. Across the United States, 20,000 trained adult Club Leaders, 5,000 Teen Ambassadors, and 450,000 youth Shooting Sports participants (age 8-18) learn marksmanship, and safe and responsible use of firearms, through its structured curriculum. Leaders from 4-H are excited to implement and study Guardian 4 Health among their Shooting Sports Clubs and communities to reduce youth firearm injury and mortality risk. Our research team will evaluate Guardian 4 Health's effectiveness, compared to usual 4-H training, in changing firearm injury prevention norms, attitudes, behavioral intention, and practice among a sample of one hundred 4-H Shooting Sports Club communities, via a Type I Hybrid randomized, controlled effectiveness trial. Aims are:

Refinement and Planning (Year 1): Adapt Guardians 4 Health for the 4-H Shooting Sports Club context Aim 1: Conduct a series of key informant interviews with an advisory panel of up to 40 key stakeholders (teen and adult 4-H Shooting Sports leaders representing a diverse group of communities and 4-H experience) to ensure The Reframe addresses 4-H-specific issues of acceptability, feasibility, and appropriateness.

Intervention Delivery (Years 2-3): Conduct a hybrid Type I effectiveness-implementation trial of Guardians 4 Health with up to 60 4-H Shooting Sports communities across the United States. For each intervention site, we will engage one Adult Site Champion in a kickoff meeting; provide materials to incorporate into standard 4-H curricula; and provide ongoing technical support. Evaluations will be conducted at 0, 3, and 6 months.

Aim 2A: Evaluate Guardian 4 Health's effectiveness, compared to usual training, in changing individual- and community-level, proximal and distal behavioral outcomes related to firearm injury prevention.

Aim 2B: Examine barriers and facilitators to implementation of Guardians 4 Health intervention using a mixed-methods (qualitative and quantitative) approach.

Aim 2C: (Exploratory) Explore injury patterns among all participating communities using population-level data.

The study will advance the science of firearm injury prevention in youth in the context of a real-world partnership between well-established firearm injury, suicide, and violence prevention researchers and the National 4-H Shooting Sports Program to conduct a rigorous experimental evaluation of a promising universal primary prevention program. Our long-term goals, consistent with CDC priorities, are to build an evidence base for best practices for individual- and community-level interventions that are easy to implement; to promote safe behaviors around firearm use and injury prevention, thereby saving lives; to meld best scientific practice with deep community-based expertise; and to create a model that can be scaled across 4-H's network, which reaches nearly 6 million youth across the nation.

Inclusion Criteria:

• Membership of child participant in local 4-H Shooting Sports Club OR
• Parent of a child participant in local 4-H Shooting Sports Club OR
• Community member of a participating local 4-H Shooting Sports Club

Exclusion Criteria:

• Non-English speakers
• Unable to consent or assent

We will provide an open dataset containing anonymized IPD that results in a publication, along with open code from our analyses, and open access to research articles. The PIs will document collected data using the Data Documentation Initiative (DDI), which is recommended by the national data archive: the Inter-university Consortium for Political and Social Research (ICPSR). Audio interviews of participants consenting to be recorded will be transcribed and de-identified; audio recordings will not be available for analysis due to concerns about re-identifiability. Transcripts will only be available with participant consent, and de-identified transcripts would be made available to other researchers via a Data Use Agreement (DUA) facilitated by ICPSR.

We will deposit the aggregate data sets, survey and semi-structured interview instruments, analysis code, NVivo codes and associated codebook and relevant README documentation files in the ICPSR data archive.

Within 30 months of completing data collection.

Data files deposited into ICPSR receive a Digital Object Identifier (DOI), which the Investigators will cite and include in all publications for the public and other researchers to locate and access the data. The Investigators will comply with the CDC Public Access Policy and upon acceptance deposit the final peer-reviewed manuscript of publications in PubMed Central (PMC), CDC Stacks, and Investigators' institutional repositories for free and public access.