Virtually every U.S. doctor practicing in a high-risk specialty will face at least one malpractice claim during their career, and even physicians in low-risk areas have a 75 percent chance of facing a suit at some point, according to a new study. At the same time, more than three-quarters of the claims do not result in any payments. The study, published in the New England Journal of Medicine on Wednesday, was based on data from 40,916 U.S. physicians enrolled in a large nationwide professional liability insurance company from 1991 through 2005.