At‐risk youth may be defined as a diverse group of young people in unstable life circumstances, who are currently experiencing or are at risk of developing one or more serious problems such as school failure or drop‐out, mental health disorders, substance and/or alcohol abuse, unemployment, long‐term poverty, delinquency and more serious criminal behaviour (Arbreton et al., 2005; Quinn, 1999). At‐risk youth typically have a multitude of social and psychological problems and typically also come from families considered at‐risk (Treskon, 2016). They may occasionally or permanently be homeless and spend time in the streets. No readily available statistics on the numbers of at‐risk youth exist but statistics on the numbers experiencing the adverse outcomes can be found. For example, according to the National Conference of State Legislatures (NCSL) on any given night, approximately 41,000 unaccompanied youth ages 13–25 experience homelessness in the United States (NCSL, 2019). It is estimated that 4.2 million youth and young adults experience homelessness each year, and that 10% of young adults ages 18–25, and at least one in 30 adolescents ages 13–17, experience some form of homelessness over the course of a year (NCSL, 2019). A substantial part of them report having a number of other problems too; for example, having substance misuse problems (29%), mental health problems (69%) or been in the juvenile justice system, in jail or detention (50%), Further, school drop‐out and no high school diploma or General Equivalency Diploma is the number one correlate for elevated risk of youth homelessness (NCSL, 2019). In Denmark the numbers are much lower. The estimated number of homeless youth, <25 years of age, was 1,036 in 2019 (Benjaminsen, 2019) which amounts to <1% of those aged 13–24 years; but in line with the evidence from the United States a large part of them have other problems (e.g., substance misuse and mental health problems) as well and the majority in the age group 18–24 are NEET, that is, neither employed nor in education or training (Benjaminsen et al., 2020). Numbers of homeless youth across Organisation for Economic Co‐operation and Development (OECD) countries are hard to locate and definitions of homelessness vary across countries (OECD, 2020a) but most likely, there is as great variation as in other indicators of at‐risk youth. For example, the rates of school drop‐out, those that do not reach a basic minimum level of skills, is on average 19% across OECD countries and range from 2% in Korea to 58% in Turkey for the 25–34 years old (OECD, 2012). Also, the NEET rates vary a lot across OECD countries; from <7% of the 15–29 year old in Iceland and the Netherlands to more than 37% in South Africa with an OECD average of 13% (OECD, 2020b). At‐risk youth are often very unlikely to seek out help for themselves within the established venues, as their adverse developmental trajectories have installed a lack of thrust in authorities such as child protection agencies and social workers (Ronel, 2006). In order to help this population, a number of outreach programmes have been established seeking to help the young people on an ad hoc basis, meaning that the interventions are designed to fit the individual needs of each young person rather than as a one‐size‐fits‐all treatment model (Korf et al., 1999; Svensson et al., 2003). The programmes are often multicomponent interventions and often rely on volunteers as outreach workers, as these are proposed to offer the young people a unique possibility for forming trusting relationships due to the fact that help is offered as an act of altruism (Ronel, 2006). The programmes may offer basic necessities such as food or shelter and they may offer counselling, mentoring and medical assistance. What define the outreach programmes is that they are targeted at helping the young people away from the streets and their current adverse developmental paths towards more stable living situations and developmental prospects. Due to the very nature of the programmes, the effects are difficult to determine. First, randomisation is difficult when there is no system of referral, and the uniquely tailored interventions, which each young person receives raises the question if one can even describe the intervention as uniform even within the same programme. Second, the aims of the programmes are typically to change the long‐term developmental paths of the participants, but longitudinal studies are often not feasible, and the establishment of long‐term preventive effects is difficult. However, even if the obstacles are many, it is still important to explore the efficacy of outreach programmes, as the stakes are extremely high. If left alone, the target population of at‐risk youth are likely to develop serious long‐term problems, which are not just detrimental to the individual but also very costly to societies.