Use of alcohol, illicit drugs, doping substances, tobacco and gambling (ANDTG) are common among young people. A large number of interventions have been developed for prevention, but the evidence for them is unclear.
The aim of this systematic review was to assess the effects of interventions to prevent misuse of alcohol, tobacco, illicit drugs and gambling in youth below 25 years. Interventions that aimed to change behavior (programs, mass media campaigns) or access (price, legislation, policies) were assessed. Both positive and negative (iatrogenic) effects were considered. This review also included health economic aspects, including a model analysis of the potential cost-effectiveness of preventing alcohol binge drinking.
The systematic review was conducted in accordance with the methodology developed by the Swedish Agency for Health Technology Assessment and Assessment of Social Services (SBU). Systematic reviews, randomized and nonrandomized controlled studies (RCT, NRCT) or interrupted time series studies (ITS) in English or Scandinavian languages and published 1990 or later were eligible for inclusion. Outcomes of interest were onset of use, consumption, drug related harm or binge drinking, measured at least six months after end of intervention. Only studies with low to moderate risk for bias were included in the analyses. The certainty of the evidence for the effects was assessed with GRADE.
The results, categorized after type of intervention, are summarized in Table 1. A major finding was that school based programs claiming to be generally drug preventive could at best prevent the misuse of a single drug. Another major finding was that no type of intervention could prevent alcohol or marijuana-use onset. Intervention effects were mostly very small or small, with effect sizes (RD or Cohen’s d) in the 1–5% range. Furthermore, most studies evaluating legislative actions, e.g. taxes, had a high risk for bias and no conclusions could be drawn.
The literature reviews on cost-effectiveness analyses of specific school based programs and of information campaigns concluded that no analyses relevant for contemporary Swedish settings are available.
A health economic model was constructed to enable cost-effectiveness analyses of alcohol prevention measures. The Markov model simulates the alcohol consumption patterns of young people aged 11 to 24 years, using the health states No Consumption, Consumption, Binge Drinking, and Death. Swedish epidemiological data was used to estimate the annual age-specific probabilities for young people to move to the Consumption state and to engage in Binge Drinking. The consequences of Binge Drinking included alcohol poisoning, accidents and violence, including related societal costs. Health effects were expressed as QALYs. An assumed 0.05 loss of quality-of-life from Binge Drinking was deducted from the assumed quality-of-life of 1 in the No Consumption and Consumption health states. Costs and QALYs were discounted 3%.
Figure 1. Health states in the Markov model.
This alcohol model was used for a threshold analysis, based on a cost-effectiveness willingness-to-pay threshold of 500 000 SEK per QALY. Two effective interventions, one specific school based program and MI (motivational interviewing), were assumed to decrease binge drinking for one year after the intervention.
The school based program, delivered at age 13 years, needed to reduce binge drinking among 14-year olds with at least 5% (i.e from a prevalence of 40% binge drinking among those that consume alcohol to a prevalence of 38%) to become cost-effective. The MI, given in a primary care setting to youths aged 18 years with a problem drinking behavior, needed to reduce binge drinking by 2.5% (from a prevalence of 60% of consumers to 58.5%).
Although there are a vast number of studies evaluating prevention interventions, few interventions have been able to demonstrate that they can deter young people from using ANDTG, and effect sizes are small or very small. Thus there is a need for new interventions, possibly based on other behavioral theories or delivered in other arenas.
How to cite this report: SBU. Interventions to prevent misuse of alcohol, drugs and gambling in youth. Stockholm: Swedish Agency for Health Technology Assessment and Assessment of Social Services (SBU); 2015. SBU report no 243 (in Swedish).
presents a comprehensive, systematic assessment of available scientific evidence. The certainty of the evidence for each finding is systematically reviewed and graded. Full assessments include economic, social, and ethical impact analyses.
SBU assessments are performed by a team of leading professional practitioners and academics, patient/user representatives and SBU staff. Prior to approval and publication, assessments are reviewed by independent experts, SBU’s Scientific Advisory Committees and Board of Directors.