Title: Economic Modelling of PHysical Activity: Simulating InterventionS (‘EMPHASIS’)
Funder: Department of Health (England)

Abstract: Background There are a number of challenges in the application of economic evaluation to public health interventions (e.g. programmes to increase physical activity (PA)), such as the attribution of outcomes to interventions, accounting for equity, and the inter-sectoral nature of costs and impact [1]. A further concern is that estimates of cost-effectiveness rarely take account of individual characteristics (e.g. age, sex, health status) that influence the uptake of PA and/or interventions [2], even when ‘healthy’ people are easily able to opt in or out of an intervention. The use of simple general economic models for what can be complex public health decision problems may not be ‘good enough’ because ignoring such heterogeneity could reduce the effectiveness and efficiency that can be gained from targeting interventions. Aim The aim is to model the cost-effectiveness, across the life course, of a range of interventions shown to be effective at increasing physical activity among people who are insufficiently active. Research plan A model will be developed to evaluate the long-term costs and health consequences of interventions to support inactive people to become more active. Longer term impacts will include the risk of developing disease conditions known to be associated with physical inactivity; coronary heart disease, stroke and type 2 diabetes. Long and short term impacts on mental health will also be included to reflect current debates and findings from our previous analyses that inclusion of short-term impacts affect advice on what interventions might be cost-effective. The model structure will be finalised during a conceptual modelling phase. We anticipate that the model will take the form of a Discrete Event Simulation (DES), extending our existing Markov model of physical activity interventions in the UK. In DES, individuals experience events (e.g. increasing PA levels, onset of heart disease, stroke, diabetes, depression or death) at times that are influenced by their attributes (e.g. age, sex, blood pressure etc.) and the interventions provided. Our research plan includes the following: Develop a ‘long list’ of interventions on which to search for best evidence Critically review economic models of physical activity interventions Develop the conceptual model Conduct a series of interlinked best evidence reviews to inform parameters for the model Build the model through to reporting tables Model verification and validation Use the model to estimate cost-effectiveness and budget impact for a range of interventions across the life course Interpret, report, share and debate potential impact of findings with range of stakeholders Research team The team comprises: Health economists with many years' experience a) conducting economic evaluation of public health interventions including physical activity b) developing decision trees, Markov and simulation models c) advising on the use of cost-effectiveness analysis in guidelines for national decision making Epidemiologists with longstanding research in the emergence of chronic diseases by age Expert systematic reviewers with expertise in physical activity and clinical medicine who have published numerous systematic reviews, including for economic models Information systems and computer simulation specialists Steering committee including national and local policy makers, clinicians, academics and two lay representatives. Potential impact/influence on the relevant policy field, users and wider stakeholders This will be the first economic analysis of physical activity interventions adopting a life course and population approach. It will therefore provide the first comparative evidence to support discussions by policy makers and practitioners of when and how to intervene to increase physical activity. This would support the recommendations of a range of policy documents e.g. 'Healthy lives, healthy people: our strategy for public health in England' [3]. It will also support decisions of where to target future research.


Research activity codes: 3.1 PRIMARY PREVENTION INTERVENTIONS TO MODIFY BEHAVIOURS OR PROMOTE WELL-BEING;8.2 HEALTH AND WELFARE ECONOMICS
Health categories: STROKE;CANCER AND NEOPLASMS;METABOLIC AND ENDOCRINE;CARDIOVASCULAR;ORAL AND GASTROINTESTINAL