Forecasting the future burden of disease in Scotland

Scotland is expected to see a rapidly ageing population within the context of an overall decrease in population. Public Health Scotland's Scottish Burden of Disease (SBoD) Study has recently been adapted to forecast how these demographic and population health trends are expected to combine, to anticipate the extent of future public health challenges. Our initial aim was to forecast the burden of disease for 12 disease groups, over the next two decades, based solely on projected changes in the population. Further work is underway looking at the additional impact of changing morbidity and mortality at individual disease level, using an age period-cohort approach, and the possible impact of disease treatment through scenario analyses. We sourced Disability-adjusted life years (DALY) rates for 12 disease groupings from the SBoD study for 2019. Age-sex specific disease burden rates were assumed to remain constant over the forecasting period, thus assuming no changes to the underlying epidemiological rates. Population projections at 5-year age group, separately for males and females, were sourced from National Records Scotland up until the year 2043. Despite a projected decrease in the Scottish population, the annual disease burden is forecast to increase 21% in the next 20 years. Absolute increases in annual disease burdens are forecast to be largest for cardiovascular diseases, cancers, and neurological diseases - together accounting for 68% of the total increase in forecasted disease burden. Forecasted relative increases in annual disease burdens highlight increases for common infectious diseases; unintentional injuries; diabetes and kidney diseases; and chronic respiratory diseases. By indicating how the changing demographic situation in Scotland will impact the causes of disease burden, these forecasts are useful to inform priorities for workforce and care service planning and redesign, and for prioritising areas for disease and injury prevention.