Reduced risk of surgical site infections through surveillance in a network

OBJECTIVE: To estimate the effect of multicentre surveillance for nosocomial infections on patients' risk of surgical site infection (SSI). DESIGN: Prospective multi-centre cohort study, from January 1996 to December 2000. SETTING: Acute care hospitals in The Netherlands. STUDY PARTICIPANTS: All 50 hospitals performing surveillance for one of seven selected procedures in the Dutch surveillance network for nosocomial infections PREZIES were invited. Thirty-seven hospitals participated (74%) and provided information on 21 920 operations, after which 885 (4%) SSI occurred. INTERVENTIONS: The surveillance comprised the following: Development of surveillance methodology by multidisciplinary team; use of a standardized registration protocol and software; regular training of data collectors; anonymous inter-hospital comparison of infection rates and feedback of results; appointment of one contact person per hospital, responsible for data collection; and dissemination of results to other health care professionals. Regular discussion of both successful and failing prevention strategies that had been instituted based on the surveillance results. OUTCOME MEASURE: Risk of SSI. RESULTS: The risk of infection was reduced for patients who had an operation during the fourth surveillance year (RR = 0.69; 95% confidence interval (CI) = 0.52-0.89) and decreased further for patients operated on during the fifth surveillance year (RR = 0.43; CI = 0.24-0.76) as compared with patients who underwent surgery within one year of the start of surveillance in their hospital. No significant risk reduction was observed for patients operated on during the second and third surveillance years. CONCLUSION: Surveillance, supported by participation in a surveillance network, reduced the risk of SSI in surgical patients registered in the Dutch surveillance network PREZIES. Our results suggest that infection control teams need to be perseverant and that surveillance programmes should be given time before evaluation.