Testing the Self-Sufficiency of Radiotherapy Catchment Areas

Abstract

Natural" catchment areas are important for supporting planning and marketing for a range of different public services, to enable improvements in access, quality and productivity. However, established methodologies used in their construction can mask varying patterns of cross-boundary movements. This issue was investigated in relation to radiotherapy services in England, using the Nomogramma di Gandy to test the degree of self-sufficiency of the 50 cancer centres' "natural" catchment areas for 2011/12. The analyses demonstrated differential patterns across the country, and highlighted that an understanding or appreciation of the volatility of patient flows relating to different catchment areas is key to risk analysis when considering future trends in radiotherapy services and referral patterns. The Nomogramma di Gandy represents a high-level filter, which complements catchment area and population methodologies, and uses simple, available data to monitor trends over time. It readily enables the interpretation of self-sufficiency and patient flow dynamics across a large number of centres. In principle, the approach should be transferable to other public services that utilise catchment areas and populations.