Over the last three years, more and more doctors have left private practice to work for hospitals. A new study has found that this trend might be contributing to the rising cost of health care, at least in the short term.

Hospital groups, which continue to be some of the biggest donors to members of Congress, wielded considerable influence during the debate over the Affordable Care Act, last year's health care reform law: during 2009 and 2010, hospital and nursing home groups spent over $216 million on lobbying, employing over 1,100 lobbyists in 2010 alone, according to the ...