Globally, alcohol was responsible for 17.6% of all injury deaths and for 7.2% of all premature mortality in 2016 . Worldwide, this proportion was highest among people aged 20 to 39 (13.5%) . Europe was the region with the highest proportions of deaths attributable to alcohol consumption in all age groups, with the highest percentage (27%) occurring in the group aged 25 to 29 years and over 15% occurring among adolescents aged 15–19 .
Worldwide, more than a quarter of all adolescents aged 15 to 19 are current drinkers (26.5%) . Although European adolescents drink less than the general population (43.8% are current drinkers, versus 59.9% of the general population), by the age of 20 to 24 years, drinking behaviour is close to that of the total population (58.4%) .
Moreover, young people tend to consume larger amounts of alcohol per occasion than adults . Heavy episodic drinking (HED) (defined as drinking five or more drinks, 60 or more grams of pure alcohol, on at least one occasion at least once per month) among young people aged 15 to 19 years is particularly prevalent in Europe (24.1%) . Despite reductions in HED among adolescents (15–19 years old) in Europe from 2000 (35.1%) to 2016 (24.1%), according to the WHO Global Status Report on Alcohol and Health 2018, levels of consumption remain dangerously high, and HED among adolescents continues to be a major public health concern .
“Binge drinking” (BD), another term for HED, has been defined as consuming five or more standard drinks per occasion for men and four or more drinks for women on the same occasion . In the countries and regions of Europe and North America, prevalence of BD increases sharply in adolescence and peaks in early adulthood (around the age of 20–25) reaching almost 40% . Subsequently, prevalence rates decrease with age. Surveys on drug and alcohol use among adolescents in secondary education in Spain (ESTUDES, 2016–2017) have shown high prevalence of BD among adolescents aged 14–18 (31.7%). 
A scarcity of literature in relation to the economic consequences (healthcare and non-healthcare costs) of BD in particular is found. In the European Union, alcohol-attributable costs in the general population were estimated at €125 billion in 2003 . We did not find any studies related specifically to costs associated with BD and underage drinking in Europe. However, previous work has shown that youthful drinkers are at greater risk of involvement in youth violence, low educational attainment and low college expectations, putting a financial burden on the criminal justice system and the education sector [7–8]. In addition to these consequences, Böckerman et al  discovered a negative association between BD, in particular, and months of employment, and subsequently also with long-term adverse long-term labor market outcomes. The foregoing suggests a need to intervene to change young people’s behaviour in relation to BD. Nowadays, a variety of interventions have been developed to tackle this public health issue (adolescent substance use) but those aimed at preventing BD specifically are scarce [10–12]. Regard to alcohol use prevention in general, a meta-analysis carried out by MacArthur et al. (2015) to investigate and quantify the effect of peer-led interventions to prevent tobacco, alcohol and/or drug use among young people concluded that such interventions may be effective, although the evidence base is limited overall and is characterized by small studies of low quality . A Cochrane systematic review carried out by Foxcroft and Tsertsvadze (2011) examined evidence on the effectiveness of universal school-based prevention programmes concluding that as small effects can provide important cost benefits for prevention programmes, studies should have sufficient statistical power to detect small effects .
Many international and national interventions have sought to prevent alcohol use among adolescents, but their cost-effectiveness has seldom been assessed, nor has the efficiency of the interventions been evaluated [7, 15, 16]. In a context of budget constraints, it seems important to study the cost-effectiveness of interventions in order to better inform health decision-making. In particular, there is a need to evaluate the cost-effectiveness of different interventions that are being, or could be, implemented to tackle the problem of BD among adolescents. In addition, World Health Organization (WHO) (2018) stablished as a priority goal to make efforts aimed at reducing “binge drinking” in populations, particularly among young people .
The aim of this current study was to analyse the cost-effectiveness and cost-utility of Alerta Alcohol, a web-based computer-tailored intervention for the prevention of binge drinking among adolescents aged 15 to 19 in Andalusia, Spain.