Temporal Changes in the Incidence and 30-Day Mortality associated with Bacteremia in Hospitalized Patients from 1992 through 2006: A Population-based Cohort Study

Background. Little is known about temporal trends in the incidence and mortality associated with bacteremia in the general population. Methods. We conducted a population-based cohort study in Northern Denmark to examine changes in bacteremia occurrence and 30-day mortality from 1992 through 2006. All patients who received a diagnosis of bacteremia were identified in a population-based bacteremia database and followed up for mortality through the Danish Civil Registry System. We determined the overall annual age- and sex-standardized rates of bacteremia episodes, the incidence of firsttime episodes, and the adjusted 30-day mortality by place of acquisition and study period. Results. We identified 14,303 bacteremia episodes, 11,703 (81.8%) of which were incident. The age- and sex-standardized overall rate of bacteremia increased by 68% from 1992 through 2006, and the incidence increased by 46% (from 114 to 166 episodes per 100,000 person-years). Community-acquired and nosocomial bacteremia incidence rates peaked at 92.1 and 77.2 episodes per 100,000 person-years in 2004 and 2002, respectively, whereas the incidence of health care-associated bacteremia increased steadily from 2.9 to 39.8 episodes per 100,000 personyears. Total number of deaths increased from 742 during 1992-1996 to 926 during 2002-2006. The 30-day mortality decreased in patients with community-acquired bacteremia (19.0% during 1992-1996 vs 15.4% during 2002-2006) but remained nearly unchanged for health care-associated (23.4% and 22.0%, respectively) and nosocomial bacteremia (27.9% and 27.7%, respectively). Conclusions. The occurrence of bacteremia in Northern Denmark, regardless of the place of acquisition, increased considerably in the past 15 years, and bacteremia was associated with persistently high 30-day mortality. Thus, bacteremia remains a clinical and public health concern.