Recently, “60 Minutes” (in my view the last bastion of great traditional network news investigative reporting) described a for-profit hospital system that apparently uses percent targets (allegedly 20%) to encourage high admission rates by their ER doctors.

In setting up this report, the reporter commented that as much as 10% of healthcare expenditures in this country were “unnecessary.”

Actually, most health experts I have read and consulted would put that number much higher — as much as 30%.

Obviously, no one knows the exact number but whatever it is, it is significant. So the question always becomes, how to stop our non-system from doing so much unnecessary care?

There are so many forces driving the delivery of unnecessary care, which I will simply define as care that makes no positive difference in the outcome for the patient. (Some unnecessary care obviously can actually harm the patient, either directly or by leading down the garden path to more unnecessary testing and treatment.)

But in my mind, the single most important factor is the absence of good information readily available in the settings of what is often labeled today as “the medical home.” Notice there are two ingredients in that formula.

When I started my television career 40 years ago, there was a paucity of good health information readily available to the public. Today there is a lot of good information but, unfortunately, it is often lost in the tsunami of information pouring over the public.

So a key factor in controlling healthcare costs and avoiding unnecessary care is helping people find – and trust – good information.

Obviously the Internet can provide such information for the savvy user. But even then, most of us will want and need someone who can help us interpret that information – and make decisions, sometimes requiring courage to “do or not to do,” based on that information.

And that brings me back to the “medical home.”

For most of us growing up, the medical home took the form of the “family doctor” or “GP.” He (few “shes” in those days) was usually a person who knew the whole family and would guide or decide the care chosen. Much of that process was based on trust between patient and doctor, trust earned over time.

In today’s fragmented, specialist-dominated healthcare world, a trusted guide is hard to find. That’s why there is so much talk about the “medical home” – a place that is available 24/7, at least by phone, that knows us and our medical history and can help us make wise decisions when we think we are sick.

But unless that “home” also has ready access to good data to help us make informed decisions, the quality of our decision-making will be potentially flawed.

Timothy Johnson trained as an emergency room physician but switched careers in 1984 when he joined ABC News as its first full time Medical Editor. Although he retired from that role in 2010, he continues as Senior Medical Contributor.  He blogs at Timothy Johnson, MD: On Health.