Medical errors and the problems they can cause — including bed sores, post-op infections and implant or device complications — cost the U.S. economy $19.5 billion in 2008, according to a study released today. (That’s enough to buy almost 1.3 billion copies of The Checklist Manifesto, Atul Gawande’s bestseller on reducing such errors via the lowly checklist.)By Katherine Hobson