Tenet Healthcare Corp. surprised Wall Street by predicting a fourth-quarter profit, but its lack of further earnings visibility highlights the toll an ailing U.S. economy and tough credit markets are taking on the hospital industry. Tenet's preliminary report may ease some of Wall Street's concerns about the final quarter of 2008, but the overall prognosis for the industry isn't encouraging, experts say. "We definitely are hearing from the field that as this economic slowdown gets longer and deeper, that hospitals are hurting," said Caroline Steinberg, vice president for trends analysis at the American Hospital Association.