BACKGROUND: We investigated the overall and daily incidence of bacteremia among hospitalized patients and evaluated the traditional classification of bacteremia (community-onset vs nosocomial based on a 48-hour time window) by means of the daily incidence and associated 30-day mortality.
METHODS: In a multicenter hospital-based cohort study, we included all patients aged 15 years or older admitted to hospitals in Funen County, Denmark, during 2000-2008, and identified all first bacteremias per admission. We calculated the overall incidence of bacteremia per 1,000 admissions and 10,000 bed-days, as well as the daily incidence of bacteremia per 10,000 bed-days and associated 30-day mortality.
RESULTS: We included 724,339 admissions and 10,281 bacteremias for an overall incidence of 14.2 per 1,000 admissions and 23.6 per 10,000 bed-days. The daily incidence was highest on the first 2 days of admission followed by lower incidences that were constant beyond day 12, but varied according to patient and epidemiologic characteristics. Thirty-day mortality for patients with bacteremia was 18% on day 1, 21% on day 2, and between 25% and 35% thereafter.
CONCLUSIONS: Hospitalized patients were at the highest risk of bacteremia during the first 2 days followed by lower incidences that were constant beyond day 12. Thirty-day mortality was 18%-21% for patients with bacteremia on the first 2 days and 25%-35% thereafter. Our findings support the traditional classification of bacteremia.