Hospital operator Tenet Healthcare Corp (THC.N) reported lower quarterly earnings, as higher bad debt expense and other costs dragged on profits in a still-weak economy, and its shares slumped more than 2 percent. Higher salary and other expenses caused four of Tenet's 50 hospitals to underperform, and the company is taking actions to improve results at those facilities, Tenet Chief Executive Trevor Fetter said on a conference call with analysts. The number of patients seeking treatment on an outpatient basis is rising, which lifted Tenet's adjusted admissions figure by 2.8 percent in the quarter.