New medical codes parse ailments to the finest detail

What's the difference if you get hurt at a Bruce Springsteen concert or a performance of "Die Fledermaus"? To your wrenched back, not much. But to the folks who process your medical records, it's a distinction worth noting. The difference between an injury at a music hall and one at an opera house is one of many thousands of details that will be parsed by a new health care classification system that begins in the U.S. on Oct. 1 — a deadline that presses on every health care provider and insurer in the nation.