U.S. News & World Report sifted through data for nearly 5,000 hospitals and results from surveys of more than 9,500 physicians to rank the best centers in 16 adult specialties from cancer to urology. Death rates, patient safety and hospital reputation were a few of the many factors taken into consideration. In the 2014-15 rankings, only 144 U.S. hospitals performed well enough to be nationally ranked in one or more specialties. Another 608 were regional high performers.