Comparison of surgical site infection rates among surgeons

Resumo

This paper presents a comparison of surgical site infection (SSI) rates among surgeons taking into account surgical procedures and risk factors. This methodological approach allows and facilitate  such comparisons as it considers potential confounding factors that may be involved. A database of 5,023 surgical procedures classified according to the National Nosocomial Infection Surveillance System (NNIS) was used to obtain adjusted SSI rates considering the surgical site and three essential variables part of the NNIS surgical risk index: (i) the ASA (American Society of Anesthesiology) physical status score; (ii) the surgical wound classification and (iii) the duration of surgery. Surgical procedures were then categorized into four risk strata: low-risk, medium low risk; medium high risk and high risk. The comparison of these rates was done using indirect standardization. The SSI rate observed for each surgeon was compared to the expected rate for the same risk strata according to the hospital database, which was taken as the reference population. Finally, dividing the number of observed SSI by the expected SSI a standardized surgical site infection ratio (SSIR) was obtained for each surgeon by procedures. The SSIR may be considered a relative, indirect and adjusted rate by risk strata, which provides a feasible alternative to compare rates among surgical teams in the same institution.

Key-words: hospital infections, surveillance, surgical site infection