Estimating and comparing the cost-effectiveness of primary prevention policies affecting diet and physical activity in England

Thesis

Health and public health services in England are under increasing financial pressure. At the same time, nearly 40% of the total disease burden is potentially amenable to known causes with two of the leading behavioural risk factors being unhealthy diets and physical inactivity. To better inform decision makers and improve health in England, this thesis aims to develop a cost-effectiveness model that can directly compare diet and physical activity interventions.

Published public health economic models were reviewed and the strengths and weaknesses of the modelling structures were explored. A pre-existing multistate life table model, PRIMEtime, was developed into PRIMEtime Cost Effectiveness (PRIMEtime CE). Disease specific NHS England costs were derived from NHS England Programme Budgeting Data and unrelated disease costs from NHS cost curves. Social care costs were quantified using a Department of Health tool for estimating wider societal costs. Disease specific utility decrements were adopted from a catalogue of EuroQoL five dimensions questionnaire scores. The cost effectiveness of reformulating food to have less salt and of expanding access to leisure centres in England were modelled from an NHS and social care perspective over a 10 year time horizon, including government and industry costs.

Salt reformulation was dominant with an estimated cost per quality adjusted life year (QALY) of -£17,000 (95% uncertainty interval, -£40,000 to £39,000), compared with £727,000 (£514,000 to £1,064,000) for increasing access to leisure centres. Sensitivity analyses and cross validation testing of outcomes demonstrated how cost per QALY estimates were sensitive to the choice of model scope, parameters, and structure.

PRIMEtime CE is a tool for decision makers to compare interventions affecting diet and physical activity, enabling them to make better informed choices about how to spend finite resources. Future work will focus on making the model freely available and expanding its risk factors to enable comparisons of other public health interventions.

Authors: Briggs, A

• DOI: 10.5287/ora-o885njxnx
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: Modelling; Public health; Multistate life table; Diet; Cost effectiveness; Health policy; Physical activity; Health economics
• Subjects: Medical sciences; Population health; Public health; Medical policy; Medical economics