Measuring Spatial Accessibility of Health Care Providers – Introduction of a Variable Distance Decay Function within the Floating Catchment Area (FCA) Method

Abstract

We integrated recent improvements within the floating catchment area (FCA) method family into an integrated ‘iFCA`method. Within this method we focused on the distance decay function and its parameter. So far only distance decay functions with constant parameters have been applied. Therefore, we developed a variable distance decay function to be used within the FCA method. We were able to replace the impedance coefficient β by readily available distribution parameter (i.e. median and standard deviation (SD)) within a logistic based distance decay function. Hence, the function is shaped individually for every single population location by the median and SD of all population-to-provider distances within a global catchment size. Theoretical application of the variable distance decay function showed conceptually sound results. Furthermore, the existence of effective variable catchment sizes defined by the asymptotic approach to zero of the distance decay function was revealed, satisfying the need for variable catchment sizes. The application of the iFCA method within an urban case study in Berlin (Germany) confirmed the theoretical fit of the suggested method. In summary, we introduced for the first time, a variable distance decay function within an integrated FCA method. This function accounts for individual travel behaviors determined by the distribution of providers. Additionally, the function inherits effective variable catchment sizes and therefore obviates the need for determining variable catchment sizes separately.

Spatial Accessibility of Primary Care in England: A Cross‐Sectional Study Using a Floating Catchment Area Method

“…In this respect, they strongly suggested a more robust assessment of the GP workforce regarding supply and demand. Therefore, the present study used a recently improved method, which is generally accepted to offer a realistic approach for the analysis of supply and demand within the GP workforce (Luo and Qi 2009;McGrail and Humphreys 2014;Bauer and Groneberg 2016). In the past, efforts have already been expended to improve patients' access to their GPs (e.g., by implementing a 7-day GP access scheme).…”

“…Generally speaking, our measure of accessibility is the ratio: Summed capacity of GP practices within a pre-specified distance of location x divided by the summed demand for services from those practices across all locations. GP accessibility was measured with the integrated Floating Catchment Area (iFCA) method (Bauer and Groneberg 2016). This method is based on the Two Step Floating Catchment Area (2SFCA) method and its improvements, for example, the enhanced (E)2SFCA method and the modified (M)2SFCA method (Luo and Wang 2003;Luo and Qi 2009;Delamater 2013).…”

Accessibility of general and specialized obstetric care providers in Germany and England: an analysis of location and neonatal outcome

“…Furthermore, this conceptualization of access only addresses potential access, which is different from patients actually visiting a certain obstetric care facility [ 17 ]. Despite these limitations, this approach is based on a valid and well established model for measuring accessibility [ 24 ]. Regarding the analysis of neonatal outcomes, it has to be noted that we used a facility-based approach (outcome data on facility level), whereas other studies used a population-based approach [ 43 , 44 ].…”

“…Accessibility was analyzed for general and specialized obstetric units. We measured accessibility with the integrated floating catchment area (iFCA) method, which generally speaking is the ratio of the summed capacity of obstetric providers within a pre-specified distance of population location x divided by the summed demand for obstetric care from those providers across all locations [ 24 ]. This method is based on the two step floating catchment area (2SFCA) method [ 25 ].…”

Multimodal Accessibility to Primary Health Services for the Elderly: A Case Study of Naples, Italy

“…Even though this number was obtained using the Euclidean distance (using network distance would have improved the analysis), it could help authorities during a first stage of analysis to identify critical areas where potential actions should be prioritized. For part of the same study area (10 counties in the Chicago area), Luo and Wang [27] compared an ordinary gravity-based measure and a two-step floating catchment area (2SFCA) method to assess accessibility to physicians. 2SFCA has been used and enhanced to include more variables and to adapt its form to the study area of interest.…”