Objective: To assess costs, health outcomes and cost-effectiveness of interventions that aim to improve quality of diet and level of physical activity in adolescents.
Design: A Markov model was developed to assess four potential benefits of healthy behaviour for adolescents: better mental health, Type 2 diabetes, higher earnings and reduced incidences of adverse pregnancy outcomes. The model parameters were informed by published literature. The analysis took a societal perspective over a 20-year period. One-way and probabilistic sensitivity analyses were conducted.
Setting: Secondary schools.
Participants: A hypothetical cohort of adolescents aged 12-13 years.
Interventions: An exemplar school-based, multi-component intervention that was developed by the Engaging Adolescents for Changing Behaviour programme, compared with usual schooling.
Primary and secondary outcome measures: Incremental cost-effectiveness ratio as measured by cost per quality-adjusted life year (QALY) gained.
Results The model suggested that an intervention for improving diet and physical activity has the potential to offer a cost-effective use of healthcare resources for adolescents in the UK at a willingness-to-pay threshold of GBP 20,000 per QALY. The key model drivers are the intervention effect on levels of physical activity, quality of life gain for high levels of physical activity, the duration of the intervention effects and the period over which effects wane.
Conclusions: The model focused on short to medium-term benefits of healthy eating and physical activity exploiting the strong evidence base that exists for this age group. Other benefits in later life, such as reduced cardiovascular risk, are more sensitive to assumptions about the persistence of behavioural change and discounting.