More evidence about over-use of procedures in health care

Ron Winslow and John Carreyrou have a piece (see here) in the Wall Street Journal about the over-use of angioplasty to clear arteries.  The authors state that:

About 600,000 angioplasty procedures, which almost always involve placement of a tiny metal tube called a stent, are done in the U.S. each year. Roughly 70% of these procedures are performed on patients suffering symptoms of a heart attack and aren't medically controversial. But the remainder are done on stable patients who are suffering mild symptoms or no symptoms at all. Of those, 50% are deemed appropriate, 38% uncertain and 12% inappropriate, the report says.

They have a very interesting graphic that illustrates their main point (click to enlarge).