Benefits of population-level interventions for dementia risk factors: an economic modelling study for England

Background: Individual-level interventions for dementia risk factors could reduce costs associated with dementia and some are cost-effective. We aimed to estimate the cost-effectiveness of population-level interventions for tackling dementia risk factors.

Methods: In this economic modelling study, we included recommended population-based interventions from a previously published review article for which there was consistent and robust evidence of effectiveness in tackling a dementia risk factor (tobacco smoking, excess alcohol use, hypertension, obesity, air pollution, and head injury). We only included interventions if they had not been introduced in England or were in place but could be extended. The interventions studied were increases in tobacco pricing, minimum pricing for alcohol, raising alcohol price, salt reduction policies, sugar reduction policies, low emission zones, and compulsory helmet use for cycling by children (aged 5-18 years). We used published intervention effect sizes and relative risks for each risk factor and a Markov model to estimate progression to dementia in populations with and without the intervention, looking at lifetime risk, in the population of England.

Findings: We estimated that reductions in excess alcohol use through minimum unit pricing would lead to cost-savings of £280 million and 4767 quality-adjusted life-years (QALYs) gained over an indefinite succession of age cohorts. Reformulation of food products to reduce salt would lead to cost-savings of £2·4 billion and 39 433 QALYs gained and reformulation to reduce sugar would lead to cost-savings of £1·046 billion and 17 985 QALYs gained. Reducing dementia risk from air pollution by introducing low emission zones in English cities with a population of 100 000 or more (that do not already impose restrictions) would lead to £260 million cost-savings and 5119 QALYs gained. Raising cigarette prices by 10% to reduce dementia risk from smoking would lead to 2277 QALYs gained and cost-savings of £157 million. Making bicycle helmets compulsory for children (aged 5-18 years) to reduce dementia risk from head injury would lead to cost-savings of £91 million and 1554 QALYs gained.

Interpretation: Population-level interventions could help tackle life course dementia risk and save costs.

Funding: UK National Institute for Health and Care Research Three Schools dementia research programme.