Levels Versus Growth Rates
[I]t is well established that some regions spend considerably more than others in the Medicare program without delivering higher-quality care or generating greater patient satisfaction.
Yet low spending is not the same as low spending growth, and even efficient areas can experience considerable spending growth. In fact, many areas that had low spending in 1992 did not have notably lower spending growth between 1992 and 2006 than other areas… Rochester, Minnesota, and Salt Lake City, for instance, are known for high-quality, integrated providers and have low Medicare spending per beneficiary. Yet between 1992 and 2006, inflation-adjusted Medicare spending per beneficiary rose 4.3% annually in Salt Lake City and 3.8% annually in Rochester, as compared with 3.2% for the country as a whole. In short, areas with exemplary delivery systems do not necessarily have exemplary rates of spending growth.
From a study Joe Newhouse and his colleagues in the New England Journal of Medicine (gated, but with abstract).