When Tanner Martin, 17, developed excruciating back pain last year, he was sure he needed an X-ray to find out what was wrong. So was his mother, who worried that the pain might indicate a serious injury that could cause permanent disability. But Konnie Martin was no ordinary parent. As chief executive officer of San Luis Valley Regional Medical Center in Alamosa, Colorado, she is at the center of an experiment, known as value-based insurance, that could transform American healthcare. One of the central features of a value-based system is a financial "stick." If patients insist on medical procedures that science shows to be ineffective or unnecessary, they'll have to pay for all or most of the cost.