title: Representativeness of the surveillance data in the intensive care unit component of the German nosocomial infections surveillance system.
abstract: OBJECTIVE
  To assess the representativeness of the data in the Krankenhaus Infektions Surveillance System (KISS), which is a nosocomial infections surveillance system for intensive care units (ICUs) in Germany.
  
  
  METHODS
  Prospective and retrospective surveillance study.
  
  
  METHODS
  Medical-surgical ICUs in Germany.
  
  
  METHODS
  A sample of medical-surgical ICUs from all over Germany, stratified according to hospital size, was randomly selected. Surveillance personnel from the hospitals were trained in surveillance of nosocomial infections, and they subsequently conducted a 2-month surveillance in their ICUs. Data were compared with KISS data for medical-surgical ICUs.
  
  
  RESULTS
  During the period from 2004 through 2005, a total of 50 medical-surgical ICUs agreed to participate in our study: 21,832 patient-days were surveyed, and 262 cases of nosocomial infection were registered, 176 of which were cases of device-associated nosocomial infection (100 cases of lower respiratory tract infection, 47 cases of urinary tract infection, and 29 cases of bloodstream infection). The overall incidence density of all types of nosocomial infections was estimated to be 10.65 cases per 1,000 patient-days. Device utilization rates in the study ICUs and in the KISS medical-surgical ICUs were similar. The pooled mean device-associated infection rates were higher in the study ICUs than in the KISS medical-surgical ICUs (10.2 vs 5.1 cases of pneumonia; 2.0 vs 1.2 cases of bloodstream infection; and 2.7 vs 1.2 cases of urinary tract infection), but the pooled mean device-associated infection rates in the study ICUs were comparable to those of the KISS ICUs during their first year of participation in KISS. The incidence density for nosocomial infections in the study ICUs varied according hospital size, with ICUs in larger hospitals having a higher incidence density than those in smaller hospitals.
  
  
  CONCLUSIONS
  KISS ICUs started with nosocomial infection rates comparable to those found in our study ICUs. Over the years of participation, however, a decrease in nosocomial infections is seen. Thus, rates of nosocomial infection from KISS should be used as benchmarks, but estimations for Germany that are based on KISS data may underestimate the real burden of nosocomial infections.
authors.affiliation: Institute of Hygiene and Environmental Medicine, Charité-University Medicine Berlin, and the National Reference Center for Surveillance of Nosocomial Infections, Berlin, Germany. Irina.Zuschneid@ba-fk.verwalt-berlin.de
authors.forename: Irina
authors.initials: I
authors.lastname: Zuschneid
authors.forename: Gerta
authors.initials: G
authors.lastname: Rücker
authors.forename: Rotraut
authors.initials: R
authors.lastname: Schoop
authors.forename: Jan
authors.initials: J
authors.lastname: Beyersmann
authors.forename: Martin
authors.initials: M
authors.lastname: Schumacher
authors.forename: Christine
authors.initials: C
authors.lastname: Geffers
authors.forename: Henning
authors.initials: H
authors.lastname: Rüden
authors.forename: Petra
authors.initials: P
authors.lastname: Gastmeier
mesh_terms: D016010:Binomial Distribution; D003428:Cross Infection / Q000453:epidemiology* / Q000209:etiology; D005858:Germany / Q000453:epidemiology; D019538:Health Care Surveys / Q000379:methods* / Q000706:statistics & numerical data; D006742:Hospital Bed Capacity / Q000706:statistics & numerical data; D006801:Humans; D015994:Incidence; D007362:Intensive Care Units / Q000592:standards / Q000706:statistics & numerical data*; D015233:Models, Statistical; D016012:Poisson Distribution; D011159:Population Surveillance / Q000379:methods*; D015203:Reproducibility of Results