Background, Existing projections of healthcare expenditure in the UK describe a wide range of possible spending futures. In part, these reflect uncertainties about growth in demand, but they also reflect differences in modelling approaches and in their underlying assumptions. The rise in healthcare demand, and its consequent impact on expenditures, has stimulated interest among policymakers in better projecting future healthcare needs to aid the management and organisation of healthcare resources. More accurate projections are expected to allow the healthcare system to adapt and prepare for future challenges. However, with a plethora of different and emerging methodologies and approaches to project future outcomes and events, it is increasingly challenging to select appropriate techniques for a given research objective such as the demand for health care, within a specific context such as the UK National Health Service (NHS).