It is perhaps better considered in terms of Indicators - all of them proxies, none of them alone sufficient; but taken together they say something worthwhile about a health care system, an episode of clinical care, the management of diseases and illness over time.

For example how do we define a “Good Driver”, perhaps by a series of Indicators of performance.

e.g. Drives 20,000 kilometres per year at least 5,000 at night

A clean, cared for vehicle,

A well maintained vehicle-serviced, safe

A clean driving licence

A maximum “no-claims bonus”