Methodology for optimising location of new primary health care facilities in rural communities: a case study in KwaZulu-Natal, South Africa.

STUDY OBJECTIVE To develop a quantitative methodology to optimally site new primary health care facilities so as to achieve the maximum population level increase in accessibility to care. The study aims to test the methodology in a rural community characterised by considerable heterogeneity in population distribution and health care access. DESIGN A geographical information system was used to estimate travel time to the nearest primary health care facility for each of the 26 000 homesteads in the subdistrict. The homestead's travel time estimate was then converted into an impedance to care estimate using distance decay (in clinic use) data obtained from the subdistrict. A map of total person impedance/km(2) was then produced using a 3 km standard Gaussian filter. The resulting map was used to site a test clinic in the largest contiguous area of high person impedance. SETTING Hlabisa health subdistrict, KwaZulu-Natal, South Africa. MAIN RESULTS The population level increase in accessibility that would be achieved by the construction of the test clinic would be 3.6 times the increase in accessibility achieved by the construction of the newest clinic in the subdistrict. The corresponding ratio for increasing clinic coverage (% of the population within 60 minutes of care) would be 4.7. CONCLUSIONS The methodology successfully identifies a locality for a new facility that would maximise the population level increase in accessibility to care. The same principles used in this research could also be applied in other settings. The methodology is of practical value in health research and practice and provides a framework for optimising location of new primary health care facilities.