Communities known for paying the most on healthcare may not be spending as much as once thought, according to new data released on Wednesday. A Thomson Reuters study, touted as the first of its kind, examined private insurance claims for 23.5 million Americans across the U.S. in 2009. The findings identified "metropolitan statistical areas" throughout the country that spent the most and least on healthcare across demographics. The study's researchers said the findings challenge the established literature that has traditionally used data from the Medicare program for the elderly to determine geographic spending variations for people of all ages. The study looked at 382 communities throughout the U.S. "The real world is actually more complicated than some people might think, and that the patterns you see for the Medicare population aren't exactly the same as the patterns you see for adults or children in the same areas," said William Marder, the study's lead author.