Tracy, overutilization can refer to physician over-ordering for defensive reasons (which physicians in the US say is increasingly normal) or to unnecessary use of expensive services like ED because people are not accessing primary care for preventive measures or to catch problems earlier. Using the ED for all your healthcare is fearfully expensive.
"... They ne'er cared for us
yet: suffer us to famish, and their store-houses
crammed with grain; make edicts for usury, to
support usurers; repeal daily any wholesome act
established against the rich, and provide more
piercing statutes daily, to chain up and restrain
the poor. If the wars eat us not up, they will; and
there's all the love they bear us."
-- Shakespeare: Coriolanus, Act 1, scene 1