According to one study, a person who shows up at an emergency room complaining of chest pain has about an 80 percent chance of being admitted and subjected to a series of sophisticated tests, even when the patient is not at high risk for heart disease and thus has an almost negligible chance of actually being ill if a few routine tests don’t turn up any irregularities. The longer round of tests carries a significant chance of falsely indicating that a key artery is clogged, and sometimes leads to the utterly unnecessary surgical insertion of a stent, accompanied by a long-term drug regimen to fight off the real risk of clotting in that stent. In this way, many healthy people each year are converted into long-term patients.