Measuring Exposure to Gun Violence and Risky Behavior: Psychometric Validation and Analysis of the Gun Violence Exposure (Gun-X) Scale.

Gun violence is a critical public health problem in the United States, requiring improved strategies for early identification and prevention. This study introduces and validates the Gun Violence Exposure (Gun-X) Scale, designed to assess awareness of gun violence, threats, and risky firearm behaviors within social networks, including in-person and digital contexts. Data were drawn from a nationally representative sample of 5,311 youth and young adults (ages 10-34) and collected from September 2023 to January 2024. Using a multi-method psychometric approach, findings supported a unidimensional structure with good reliability and consistent model fit across training and validation samples. Item Response Theory analyses indicated high discrimination across items and strongest measurement precision at moderate levels of exposure. Convergent validity was supported through associations with violence exposure, peer gun carrying, and neighborhood risk, while discriminant validity was demonstrated with mental health and social support measures. The 10-item Gun-X Scale provides a reliable and generalizable measure of bystander exposure to gun violence. It has applications in research, clinical screening, and prevention efforts, particularly for characterizing exposure patterns and informing tailored, context-sensitive responses. The scale is intended to assess exposure and should not be used as a standalone tool for selecting individuals for intervention roles.