ObjectivesThis study aimed to clarify the relationship between the institution and resident with respect to accessibility to acute ischemic stroke (AIS) treatment in Hokkaido and to propose new methodology monitoring for accessibility to healthcare resources. MethodsThis study involves the use of geographic information system (GIS) network analysis. We established hospital/clinic with one of the following conditions as resources for AIS treatment: (1) medical facility practicing AIS treatment, (2) having computed tomography (CT) equipment, (3) having angiography equipment, and (4) having AIS specialists (neurosurgeons). We evaluated the coverage of population resources using transport time between ambulance departure and arrival at the healthcare facility. Furthermore, we compared the population coverage rate using available resources and calculated a Gini coefficient to analyze its relation with inequality. Empirical analysis was performed, and public database for data collection was utilized. We calculated the rate of population coverage with a transport time within 10 min as an indicator of accessibility to medical resources by GIS. ResultsThe Gini coefficients of practicable facilities, CT, angiography, and neurosurgeons are 0.35, 0.16, 0.18, and 0.30, respectively. The inequality of accessibility differs depending on the resources, and Gini coefficients indicate that hospital/clinic and neurosurgeons were considered to have higher allocation inequalities than CT and angiography. ConclusionsCombining Gini coefficient and GIS network analysis in accessibility can be useful in quantifying and monitoring variation by region. We propose this combination as a new method for helping the government to make evidence-based healthcare planning.