A real-world, bottom-up cost of illness analysis of type 2 diabetes mellitus from a tertiary hospital in Saudi Arabia

Type 2 diabetes mellitus (T2DM) is a major contributor to global morbidity, mortality, and healthcare expenditure. In the context of Saudi Arabia, it is concerningly notable that the prevalence of T2DM is particularly high and rising. Existing cost estimates have previously relied rely on aggregate methodologies, potentially an approach that limits their usefulness for hospital-level decision-making. Accordingly, the primary goal in the current study was to estimate the direct medical costs of T2DM using a real-world, bottom-up micro-costing approach. We carried out a retrospective, cross-sectional cost-of-illness study using electronic medical records from a tertiary hospital in Saudi Arabia. The data collection happened between January and December, 2024. We included adult patients with T2DM, and we calculated direct healthcare costs from the hospital payer perspective, including outpatient care, hospitalizations, laboratory investigations, and medications. In data analysis, we used descriptive statistics, one-way ANOVA, and log-transformed ordinary least squares regression in order to assess cost differences and identify predictors of total cost. A total of 431 patients participated and findings showed that the mean annual cost per patient was SAR 15,396.24 (4,103 USD), and a total cost of SAR 6,635,779.57 (1,768,209 USD). Medications (52.9%) and laboratory tests (40.6%) were the main cost drivers, and higher costs were significantly associated with elevated glycated hemoglobin levels (β = 0.067, p < 0.001), longer disease duration (β = 0.019, p = 0.003), and greater number of comorbidities (β = 0.070, p < 0.001). Going from the above findings, we concluded that T2DM imposes a substantial economic burden on tertiary healthcare systems, importantly indicating that improving glycemic control and managing comorbidities may reduce costs and enhance healthcare efficiency.