Background: The NNIS risk index has been largely recommended because it consists of a simple additive scale. Nevertheless, it has been seldom validated in populations other than the NNIS participating hospitals
Objectives: To investigate the occurrence of Surgical Site Infection ( SSI ) using the traditional variables of the NNIS Index, and to approach the suitability of this methodology when applied to a smaller public university hospital (HU/UFSC) in Florianópolis, South Brazil.
Methods: A retrospective chart review of 9322 patients undergoing surgical procedures in the period of January 1993 to December 1998.
Results: The composite index showed to be a better predictor of SSI than Surgical Wound class (SWc) and presented a predictive power comparable to the ASA index. ASA together with length of surgery seemed to be the main contributors for the final performance of the composite index.
Conclusions: The composite index using the variables of the traditional NNIS system showed to adequately predict the risk of SSI in our university hospital. Larger samples using different hospitals with similar characteristics are needed to approach the risk of SSI associated to specific surgical procedures.