Making the case for a 'fifth wave' in public health.

This paper will argue that the UK has seen several phases of public health improvement since the Industrial Revolution, and that each of these can be linked to major shifts in thinking about the nature of society and health itself. The authors are not, however, attempting to delineate firm sequences of events (or imply causality) as this would require a level of analysis of the relationship between economy, society and culture which is beyond the scope of this paper. Rather, it is suggested that each phase of health improvement can be thought of in metaphorical terms as a 'wave'. The first wave is associated with great public works and other developments arising from social responses to the profound disruptions which followed the Industrial Revolution. The second wave saw the emergence of medicine as science. The third wave involved the redesign of our social institutions during the 20th Century and gave birth to the welfare state. The fourth wave has been dominated by efforts to combat disease risk factors and the emergence of systems thinking. Although a trough of public health activity continues from each wave, none exerts the same impact as when it first emerged. This paper will discuss the complex challenges of obesity, inequality and loss of wellbeing, together with the broader problems of exponential growth in population, money creation and energy usage. As exponential growth is unsustainable on a finite planet, inevitable change looms. Taken together, these analyses suggest that a fifth wave of public health development is now needed; one which will need to differ radically from its forerunners. The authors invite others to join them in envisioning its nature and in furthering the debate about future public health.