National Study of Antibiotic Use in Emergency Department Visits for Pneumonia, 1993 Through 2008

 0.055). Overall, 66% of adult patients with a primary diagnosis of pneumonia had documentation of an antibiotic administered while in the ED. There was an increase in antibiotic administration for adults with pneumonia from 1993 through 2008 (49% to 80%; p trend < 0.001). Specifically, there was an increase in use of macrolides from 1993 to 2006 (20% to 30%, p trend < 0.001) and a marked increase in use of quinolones from 0% to 39% from 1993 through 2008 (p trend < 0.001). Penicillin and cephalosporin use remained stable. Use of an antibiotic consistent with 2007 IDSA/ATS guidelines increased from 22% (95% confidence interval