Surgical Site Infections in a High Outlier'' Institution: Are Colorectal Surgeons to Blame?

PURPOSE: In 2006, the Cleveland Clinic was a high outlier'' for surgical site infections in the National Surgical Quality Improvement Program. Because this finding may be due to a high proportion of colorectal procedures at the Cleveland Clinic, the purpose of the present study was to compare the national and Cleveland Clinic databases regarding proportion of colorectal procedures and to investigate the frequency of SSI after colorectal versus general and vascular surgery and the factors that predict risk of SSI. METHODS: Logistic regression analysis was used to analyze patient and procedure factors in cases with and those without surgical site infections from the Cleveland Clinic's National Surgical Quality Improvement Program database. RESULTS: Compared with the national database, the Clinic database had a significantly higher proportion of patients who had undergone colorectal procedures: 9.4 percent (11,102/118,391) vs. 17.0 percent (280/1,646) (P < 0.05). The overall surgical site infection (SSI) rate was 5.6 percent for the national database and 9.4 percent for the Clinic. However, in both databases, SSI rates were considerably higher for colorectal procedures than for general and vascular surgery: Clinic, 14.3 percent for colorectal and 9.4 percent for general and vascular procedures (P < 0.05); national database, 15.7 percent for colorectal and 5.6 percent for general and vascular (P < 0.05). Patient-related risks for surgical site infection in colorectal cases were body mass index >30, platelet count <150/mu l, age >55. Procedure-related risk was operation duration >180 min (all P < 0.05). CONCLUSION: Participation in the National Surgical Quality Improvement Program brought attention to our high rate of SSI, which appeared to be due to a high proportion of colorectal patients, a high-risk subset. Further analysis identified unique SSI risk factors in this subgroup; most are not amenable to modification. Colorectal surgery may require unique risk adjustment for SSIs because of the nature of the operations and inherent risk of SSIs.