Estimates of non-communicable disease expenditure by disease phase, sex, and age group for all OECD countries.

Background: NCD expenditure estimates are necessary to estimate future health system expenditure trajectories for different prevention and treatment policies. However, no dataset of comparable estimates exists across OECD countries. This study generates disease expenditure estimates for all 38 OECD member countries in 2019, for 80 major NCDs by disease phase, sex, and age group.

Methods: Australian health expenditure (per person) by sex and age group was disaggregated by disease phase (first year of diagnosis, last year of life if dying of disease, otherwise prevalent) using Global Burden of Disease (GBD) data and New Zealand estimates of relative expenditure ratios by phase. These estimates were applied to GBD estimated case numbers in each OECD country and scaled to each country's total health system expenditure to estimate expenditure by NCDs in 2019. OECD purchasing power parities were used to adjust estimates to United States (US) dollars for cross-country comparability. Comparisons were made to pre-existing disease expenditure estimates for Norway, Switzerland, and the US.

Results: Average NCD expenditure across OECD countries was US$207 million per 100,000 population. Pooled across countries, musculoskeletal disorders had the highest proportion of total health expenditure (17.4%), followed by cancer (9.4%), and cardiovascular diseases (CVD) (9.1%). Within diseases, the percentage of expenditure was higher for females for musculoskeletal disorders (56.1%), mental and substance use disorders (55.8%), and neurological conditions (54.8%). For males, it was kidney and urinary diseases (63.8%), cancer (58.3%), and CVD (50.7%). First year of diagnosis represented on average 36.8% of total NCD expenditure, while last year of life expenditure accounted for 2.6%. While there were similarities between our expenditure estimates and pre-existing country-specific estimates for Norway, Switzerland and the US, notable differences were observed for musculoskeletal disorders, cancer, and mental and substance use disorders.

Conclusions: Our estimates represent a starting point for a cross-national dataset of disease-specific expenditure that can be used to forecast future expenditure and potential health system cost savings of preventive and treatment policies. We recommend evolving our paper's methods to include multiple country-level studies as inputs - augmented by covariates (e.g. GDP, public/private split) to better predict disease expenditure.