Trends in Hospitalizations with Antibiotic-Resistant Infections: U.S., 1997-2006

Objectives. Antibiotic resistance is a significant global problem, but the trends in prevalence and impact of antibiotic resistance in hospitalizations in the United States are unclear. We evaluated the trends in hospitalizations associated with antibiotic-resistant infections in U.S. hospitals from 1997 to 2006. Methods. We analyzed the National Hospital Discharge Survey (NHDS) during 1997-2006 (unweighted n=3.3 million hospitalizations; weighted n=370.3 million hospitalizations) and examined trends in prevalence of hospitalizations with antibiotic-resistant infections, length of stay, and discharge status. Results. The number of infection-related hospitalizations with antibiotic resistance increased 359% during the 10-year period, from 37,005 in 1997 to 169,985 in 2006. The steepest rise was seen among individuals < 18 years of age. The mean age of individuals with infection-related hospitalizations that had antibiotic-resistant infections decreased substantially, from 65.7 years (standard error [SE] = 2.01) in 1997 to 44.2 years (SE=1.47) in 2006. As the proportion of patients with antibiotic-resistant infections who did not have insurance increased, the length of stay for those hospitalizations had a corresponding decrease (r=0.91, p< 0.01). Conclusions. Antibiotic-resistant infections are becoming increasingly commonplace in hospitalizations in the U.S., with a steady upward trend between 1997 and 2006. Antibiotic-resistant infections are increasingly being seen in younger patients and those without health insurance.