Figure 1

(a) Map of KwaZulu-Natal, indicating (with black crosses) the location of the 17 health care facilities (HCFs) that have been designated for ART rollout by the South African Government, and the spatial distribution of communities distinguished by the number of PLWHA (by both size and color). Durban is the capital city of the province and has more PLWHA than any other community, followed by the cities of Pietermaritzburg and Newcastle; these urban cities are represented by the large red unfilled diamonds. We exclude these three large urban cities and analyze treatment accessibility only for rural communities. (b) Two-dimensional form of a simple function that describes accessibility to ART (assuming that the catchment area has a radius of 10 km). The mathematical form of this accessibility measure is known as a Gaussian, f(d) = exp (-kd ²). The catchment area radius is defined as the distance where treatment access is reduced to 1% relative to access at a given HCF; the catchment radius is used to calculate the access-scaling parameter k in the treatment-accessibility function.