The U.S. ranks as the worst performer among 10 developed nations in critical areas of healthcare, including preventing deaths, access (mainly because of high cost) and guaranteeing quality treatment for everyone, regardless of gender, income or geographic location, according to the report, published Thursday by The Commonwealth Fund. Based on the new findings, people in the U.S. die the youngest and experience the most avoidable deaths, even though the country spends nearly twice as much — about 18% of gross domestic product — on healthcare than any other nation ranked. Thursday's findings show, the researchers say, that the U.S. spends the most but gets the least from its investment. Ironically, the steep price people pay doesn’t guarantee superior care. The findings were based on tens of thousands of survey responses from primary care physicians and residents in high-income countries collected over the last three years.