Attributable one-year healthcare cost of incident type 2 diabetes: A population-wide difference-in-differences study in Denmark.

Aim: The aim of this study is to estimate the causally attributable one-year healthcare costs for individuals getting a type 2 diabetes diagnosis compared to a matched sample and show the incurred costs of medication and in primary and secondary healthcare.

Methods: Causal estimation using a difference-in-differences design to estimate the one-year health care costs attributable to type 2 diabetes. Danish registry data consisting of the entire population in years 2016-2019. Newly diagnosed individuals with type 2 diabetes in 2018 were identified using a validated method. Sociodemographic and historical health data were used to identify a matched control group. Individuals were followed for two years before and one year after the date of diagnosis using. Three cost components were analysed: medication and primary and secondary healthcare costs.

Results: A total of 18,133 individuals were diagnosed with type 2 diabetes in 2018 and matched successfully 1:1 to a control group. The total attributable one-year cost of type 2 diabetes was EUR 1316. The main cost component was hospital care (EUR 1004) and primary care (EUR 167). The total attributable cost of incident diabetes in Denmark in 2018 was approx. EUR 24 million.

Conclusions: The majority of the first year health care cost of incident diabetes is incurred at the hospital level followed by primary care and medication. Our yearly cost estimate per newly diagnosed is considerably lower than estimates from the US and Australia.