Presentation (CTI)

OBJECTIVES: Estimating healthcare costs attributable to specific diseases is widespread, yet remains challenging. Previous work evaluated costs attributable to cardio- and cerebrovascular events using regression models. This study extends prior methodologies from to the outpatient setting to estimated disease-attributable costs in a general population using a Japanese insurer-based IQVIA Claims Database covering all age groups.
METHODS: This study investigated disease-attributable healthcare costs among individuals with outpatient claims in April 2023 who remained in the cohort through March 2024. Diseases were defined using three-digit ICD-10 codes and dialysis-related medical service fee codes. The impact of each disease on annual outpatient costs was assessed using a Lasso model including all three-digit ICD-10 codes and dialysis indicators. Monthly disease-attributable outpatient costs were then estimated using a fixed-effects panel data regression model with time fixed effects. The primary analysis employed a linear fixed-effects model, while sensitivity analyses used a log-transformed model with Duan’s smearing estimator. Costs were estimated for each age group as well as for the overall population.
RESULTS: A total of 2,892,855 individuals were included. Of these, 644,878 (22.3%) were aged <15 years, 705,862 (24.4%) were aged 15-44 years, 1,314,401 (45.4%) were aged 45-64 years, and 227,714 (7.9%) were aged ≥65 years. The most prevalent diseases among individuals aged <15 years were respiratory conditions, including J06 (74.5%) and J30 (73.4%), whereas among individuals aged ≥65 years, hypertension (I10: 64.2%) and dyslipidemia (E78: 56.3%) were most common. Hereditary factor VIII deficiency (D66), mucopolysaccharidosis (E76), and meningococcal infection (A39) were identified as having the largest impact on annual outpatient costs.
CONCLUSIONS: Preliminary analyses identified prevalent diseases in the general population of the IQVIA Claims Database, as well as conditions associated with outpatient healthcare costs. Ongoing analyses will estimate monthly attributable costs for diseases in outpatient settings across age groups and compare the associated cost burden.