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Structure, Process, and Outcome Quality of Surgical Site Infection Surveillance in Switzerland

  • Stefan P. Kuster (a1) (a2), Marie-Christine Eisenring (a1) (a3), Hugo Sax (a1) (a2), Nicolas Troillet (a1) (a3) (a4) and Swissnoso...



To assess the structure and quality of surveillance activities and to validate outcome detection in the Swiss national surgical site infection (SSI) surveillance program.


Countrywide survey of SSI surveillance quality.


147 hospitals or hospital units with surgical activities in Switzerland.


Site visits were conducted with on-site structured interviews and review of a random sample of 15 patient records per hospital: 10 from the entire data set and 5 from a subset of patients with originally reported infection. Process and structure were rated in 9 domains with a weighted overall validation score, and sensitivity, specificity, positive predictive value, and negative predictive value were calculated for the identification of SSI.


Of 50 possible points, the median validation score was 35.5 (range, 16.25–48.5). Public hospitals (P<.001), hospitals in the Italian-speaking region of Switzerland (P=.021), and hospitals with longer participation in the surveillance (P=.018) had higher scores than others. Domains that contributed most to lower scores were quality of chart review and quality of data extraction. Of 49 infections, 15 (30.6%) had been overlooked in a random sample of 1,110 patient records, accounting for a sensitivity of 69.4% (95% confidence interval [CI], 54.6%–81.7%), a specificity of 99.9% (95% CI, 99.5%–100%), a positive predictive value of 97.1% (95% CI, 85.1%–99.9%), and a negative predictive value of 98.6% (95% CI, 97.7%–99.2%).


Irrespective of a well-defined surveillance methodology, there is a wide variation of SSI surveillance quality. The quality of chart review and the accuracy of data collection are the main areas for improvement.

Infect Control Hosp Epidemiol 2017;38:1172–1181


Corresponding author

Address correspondence to Stefan Kuster, MD, MSc, Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, Raemistrasse 100 / HAL14 D6 8091 Zürich, Switzerland (


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PREVIOUS PRESENTATION: These data were presented in part at the Fourth International Conference on Prevention & Infection Control (ICPIC) on June 23, 2017, in Geneva, Switzerland


Authors of equal contribution.


Members of Swissnoso are (in alphabetical order): Carlo Balmelli, MD, Lugano; Marie-Christine Eisenring, RN, ICP, CNS, Sion; Stephan Harbarth, MD, MS, Geneva; Stefan P. Kuster, MD, MSc, Zurich; Jonas Marschall, MD, MSc, Bern; Virginie Masserey Spicher, MD, Bern; Didier Pittet, MD, MS, Geneva; Christian Ruef, MD, Zurich; Hugo Sax, MD, Zurich; Matthias Schlegel, MD, St. Gallen; Alexander Schweiger, MD, Basel; Nicolas Troillet, MD, MSc, Sion; Andreas F. Widmer, MD, MSc, Basel; Giorgio Zanetti, MD, MSc, Lausanne.



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