Methodology of the Norwegian Surveillance System for Healthcare-Associated Infections: The value of a mandatory system, automated data collection, and active postdischarge surveillance

BackgroundSurveillance is a primary component of systems for the prevention of health care-associated infections (HCAI). Feedback to surgeons from these surveillance systems may reduce rates of surgical site infections (SSIs) by approximately 20%.ObjectiveOur objective was to describe the Norwegian Surveillance System for Healthcare-Associated Infections’ (NOIS) module for SSI (NOIS-SSI) and to evaluate the completeness of hospital participation, the effectiveness of automated data collection, and the added value of follow-up after hospital discharge during 2005 to 2009.MethodsNOIS was introduced by regulation in 2005. Hospital participation is described through adherence to the mandatory requirements and participation in the voluntary aspects of the system. Automated data collection is evaluated through the completeness of reporting of explanatory and administrative variables. The impact of active postdischarge surveillance is assessed through the completeness of follow-up and the proportion of infections detected after hospital discharge.ResultsThe system has achieved 95% (52/55) hospital participation, with 65% (34/52) of the hospitals submitting more data than the required minimum. The completeness of patient and procedure-related background data is satisfactory, with 23.3% (5,079/21,772) of the records having at least 1 missing value. The completeness of 30-day follow-up of patients is 90.7% (19,747/21,772), and 81% (765/948) of the infections were detected after discharge from hospital.ConclusionImplementation of a new surveillance system for SSI has been successful evaluated through hospital participation, the completeness of reporting of explanatory and administrative variables, and the completeness of postdischarge follow-up. Important success factors are a mandatory system, automated data-harvesting systems in hospitals, and active postdischarge surveillance.