Intimate partner
Intimate partner violence refers to behaviour in an intimate relationship that causes physical, sexual or psychological harm, including physical aggression, sexual coercion, psychological abuse and controlling behaviours.Population-level surveys based on reports from victims provide the most accurate estimates of the prevalence of intimate partner violence and sexual violence in non-conflict settings. A study conducted by WHO in 10 mainly developing countries found that, among women aged 15 to 49 years, between 15% (Japan) and 70% (Ethiopia and Peru) of women reported physical and/or sexual violence by an intimate partner. A growing body of research on men and intimate partner violence focuses on men as both perpetrators and victims of violence, as well as on how to involve men and boys in anti-violence work.Intimate partner and sexual violence have serious short- and long-term physical, mental, sexual and reproductive health problems for victims and for their children, and lead to high social and economic costs. These include both fatal and non-fatal injuries, depression and post-traumatic stress disorder, unintended pregnancies, sexually transmitted infections, including HIV.Factors associated with the perpetration and experiencing of intimate partner violence are low levels of education, history of violence as a perpetrator, a victim or a witness of parental violence, harmful use of alcohol, attitudes that are accepting of violence as well as marital discord and dissatisfaction. Factors associated only with perpetration of intimate partner violence are having multiple partners, and antisocial personality disorder.
Despite this, force is used routinely against juveniles by police. In 1974, the US Department of Justice assumed primary responsibility for delinquency prevention programmes and created the Office of Juvenile Justice and Delinquency Prevention, which has supported the "Blueprints for violence prevention" programme at the University of Colorado Boulder. Public health
The public health approach is a science-driven, population-based, interdisciplinary, intersectoral approach based on the ecological model which emphasizes primary prevention. Rather than focusing on individuals, the public health approach aims to provide the maximum benefit for the largest number of people, and to extend better care and safety to entire populations. The public health approach is interdisciplinary, drawing upon knowledge from many disciplines including medicine, epidemiology, sociology, psychology, criminology, education and economics. Because all forms of violence are multi-faceted problems, the public health approach emphasizes a multi-sectoral response. It has been proved time and again that cooperative efforts from such diverse sectors as health, education, social welfare, and criminal justice are often necessary to solve what are usually assumed to be purely "criminal" or "medical" problems. The public health approach considers that violence, rather than being the result of any single factor, is the outcome of multiple risk factors and causes, interacting at four levels of a nested hierarchy (individual, close relationship/family, community and wider society) of the Social ecological model. From a public health perspective, prevention strategies can be classified into three types:

Primary prevention – approaches that aim to prevent violence before it occurs.