ABSTRACT
A major contribution to the complexity of healthcare is that there is a great deal of controversy about diagnoses, including the status of some diagnoses and indeed whether they exist at all, and much the same dispute about treatments. An engineer designing a bridge will use Newtonian physics about mass and gravity, while a nuclear scientist will employ quantum physics. In healthcare, the linear explanation that aetiology A causes condition B and that therapy C will put it right is economically satisfactory for a great many conditions. The wider healthcare issues that are now taken for granted require that the old linear models of explanation need supplementing by systems models. In essence, it is the problem of escalating demand for healthcare responses to conditions which are undefined and potentially unlimited. Thus there is an enormous and ever-expanding demand for an unspecified, fuzzy notion of what healthcare should take under its wings.
