Bayesian spatial models of the association between interpersonal violence, animal abuse and social vulnerability in São Paulo, Brazil

Animal abuse adversely affects animal health and welfare and has been associated with interpersonal violence in studies of individuals. However, if that association also depends on sociocultural contexts and can be detected on a geographic scale, a wider source of data can be used to identify risk areas to support the surveillance of both types of violence. In this study, we evaluated the association between interpersonal violence notifications, animal abuse notifications and an index of social vulnerability in São Paulo City, on a geographic scale, using Bayesian spatial models. The social vulnerability index was a risk factor for the number of interpersonal violence notifications and presented a dose-response pattern. The number of animal abuse notifications was also a risk factor for the number of interpersonal violence notifications, even after controlling for the social vulnerability index. The incorporation of spatial effects produced marked improvements in model performance metrics and allowed the identification of excess risk clusters. Geographical data on notifications on either animal abuse or interpersonal violence should be considered incitement for investigations and interventions of both types of violence. We suggest that notifications of animal abuse be based on an explicit definition and classification, as well as on objective measurements that allow a better understanding of the species and type of abuse involved, the animal health consequences, and the context in which they occurred.