Jaime Rosenthal, a senior at Washington University in St. Louis, called more than 100 hospitals in every state last summer, seeking prices for a hip replacement for a 62-year-old grandmother who was uninsured but had the means to pay herself. Only about half of the hospitals, including top-ranked orthopedic centers and community hospitals, could provide any sort of price estimate, despite repeated calls. Those that could gave quotes that varied by a factor of more than 10, from $11,100 to $125,798. Rosenthal's grandmother was fictitious, created for a summer research project on health care costs. But the findings, which form the basis of a paper released Monday by JAMA Internal Medicine, [highlight] the unsustainable growth of U.S. health care costs and an opaque medical system in which prices are often hidden from consumers. Although many experts have said that Americans must become more discerning consumers to help rein in health care costs, the study illustrates how hard that can be. Researchers emphasized that studies have found little consistent correlation between higher prices and better quality in U.S. health care. Cram said there was no data that Mercedes" hip implants were better than cheaper options, for example. Jamie Court, the president of Consumer Watchdog in Santa Monica, said: "If one hospital can put in a hip for $12,000, then every hospital should be able to do it." With such immense variation in prices, he said, "There is no real price. It's about profit."