Hierarchical two-step floating catchment area (2SFCA) method: measuring the spatial accessibility to hierarchical healthcare facilities in Shenzhen, China

Abstract

Background Spatial accessibility to healthcare facilities has drawn much attention in health geography. In China, central and local governments have aimed to develop a well-organized hierarchical system of healthcare facilities in recent years. However, few studies have focused on the measurement of healthcare accessibility in a hierarchical service delivery system, which is crucial for the assessment and implementation of such strategies. Methods Based on recent improvements in 2SFCA (two-step floating catchment area) method, this study aims to propose a Hierarchical 2SFCA (H2SFCA) method for measuring spatial accessibility to hierarchical facilities. The method considers the varied catchment area sizes, distance decay effects, and transport modes for facilities at various levels. Moreover, both the relative and absolute distance effects are incorporated into the accessibility measurement. Results The method is applied and tested in a case study of hierarchical healthcare facilities in Shenzhen, China. The results reveal that the general spatial accessibility to hierarchical healthcare facilities in Shenzhen is unevenly distributed and concentrated. The disparity of general accessibility is largely caused by the concentrated distribution of tertiary hospitals. For facilities at higher levels, average accessibility of demanders is higher, but there are also larger disparities in spatial accessibility. The comparison between H2SFCA and traditional methods reveals that traditional methods underestimate the spatial disparity of accessibility, which may lead to biased suggestions for policy making. Conclusions The results suggest that the supply of healthcare resources at primary facilities is far from sufficient. To improve the spatial equity in spatial accessibility to hierarchical healthcare facilities, various actions are needed at different levels. The proposed H2SFCA method contributes to the modelling of spatial accessibility to hierarchical healthcare facilities in China and similar environments where the referral system has not been well designed. It can also act as the foundation for developing more comprehensive measures in future studies.

A Data-Driven Method for Measuring Accessibility to Healthcare Using the Spatial Interpolation Model

“…The two-step floating catchment area method incorporates the capacity of services, the population distribution, and the travel resistance from demand locations to healthcare services as indicators [10], and it is one of the most important methods used to evaluate spatial accessibility to healthcare [11]. The improved model further considers different catchment area sizes, distance attenuation effects [12], and the transportation modes of different levels of facilities [13]. The supplydemand ratio is calculated based on the catchment area, which is the area of space covered by facilities or people within a spatial barrier threshold (travel time or distance).…”

An integrated analysis of spatial access to the three-tier healthcare delivery system in China: A case study of Hainan Island

“…The fusion of availability and accessibility has been referred to as "spatial access", which accounts for the spatial barriers that consumers must overcome to receive services [8]. Spatial access (e.g., dimensions 1-2) is also interpreted as potential access, which considers the possibility that people can access services, while revealed access depends on the willingness, preferences, and choices of individuals [9]. As an effective indicator, potential spatial access has been widely used in previous studies to measure access to healthcare and estimate equity [10].…”

“…A number of improvements have been proposed based on the 2SFCA, and they can be classified into four types [9]. The first modifies the distance decay function, which models the likelihood trend that choosing a healthcare institution would decrease as the distance increases [29,30].…”

“…Second, which tiers and/or types of healthcare institutions being considered depend on individual research questions. In most cases, the catchment area sizes of different tiers/levels/types of healthcare institutions are set differently, and general access is calculated as the sum of access for all healthcare institutions [9,47]. However, Zhang et al [48] measured shortest travel time to city-level hospitals, county-level hospitals, and community-level health centers, identifying different types of healthcare resource shortage areas.…”

Spatial accessibility assessment to healthcare facilities: urban and rural areas

“…The results show that public health facilities within the study area were grouped in a distribution with central regions having high density of facilities and peripheral regions having low density. In order to assess this from a transport perspective it is crucial to understand the availability of health facilities and intensive care beds in urban and rural areas [11].…”