OBJECTIVE:We sought to evaluate the short- and long-term resource utilization and costs associated with ICH, taken from an entire population. We additionally sought to evaluate the association of oral anticoagulation (OAC) and healthcare costs.METHODS:Retrospective cohort study of adult patients (≥18 years) with ICH in the entire population of Ontario, Canada (2009-2017). We captured outcomes through linkage to health administrative databases. We used generalized linear models to identify factors associated with total cost. Analysis of OAC use was limited to patients ≥ 66 years. The primary outcome was total 1-year direct healthcare costs in 2020 US dollars.RESULTS:Among 16,248 individuals with ICH (mean age: 71.2 years, male: 52.3%), 1-year mortality was 46.0%, and 24.2% required mechanical ventilation. The median total 1-year cost was $26,886 [(interquartile range [IQR]) 9,641-62,907] with costs for those who died in hospital of $7,268 (IQR 4,031-14,966) versus $44,969 (IQR 20,264-82,414, P < 0.001) for survivors to discharge. Oral anticoagulation (OAC) use (analysis limited to individuals ≥ 66 years old) was associated with higher total 1-year costs (cost ratio 1.06 [95% confidence interval: 1.01-1.11]). Total 1-year costs for the entire cohort exceeded $120 million per year over the study period.CONCLUSIONS:ICH is associated with significant healthcare costs, and the median cost of an ICH patient is roughly 10-times the median inpatient cost in Ontario. Costs were higher among survivors than deceased patients. OAC use is independently associated with increased costs. In order to maximize cost-effectiveness, future therapies for ICH must aim to reduce disability, and not only improve mortality.