A connectivity-based index of healthcare accessibility using a spatial interaction approach

In large, heterogeneous regions, healthcare systems are often centralized in major urban centers, forcing residents of peripheral areas to travel considerable distances to obtain care. Mobility related to healthcare, however, is not captured by standard development metrics, even though geographic connectivity, travel feasibility, and local healthcare capacity are crucial for determining whether individuals can realistically access services. An index that integrates these dimensions is therefore essential to identify and address inequalities in accessibility. To this end, we propose a model that combines road connectivity between locations with the distribution of healthcare personnel. The model is operationalized as a weighted, directed network, where edge weights are derived from a gravity-based function representing travel costs. We apply this approach to the state of Jalisco, Mexico, where healthcare services are concentrated in the Guadalajara Metropolitan Area and a few socioeconomically advantaged municipalities. To validate the proposed index, we show that it aligns strongly with the Human Development Index at the local level.