Methods: We performed a retrospective cohort study of adult patients who underwent COLO procedures between Jan 15, 2015, and June 16, 2016, in a large cohort (n=37, median bed size=214; interquartile range [IQR] 142, 290) of community hospitals. SSI was defined using CDC/NHSN criteria; surveillance was performed systematically across all study hospitals. We collected data on several potential risk factors, including age, gender, body mass index (BMI), diabetes, American Society of Anesthetists (ASA) score, wound classification, operation time, emergency status, procedure types, hospital bed size (small ≤ 200 beds), and annual volume (<100 COLO = low volume; ≥100 COLO = high volume). We created a multivariable logistic regression model to identify factors independently associated with SSI. Two-sided P values of less than 0.05 were used to indicate statistical significance.
Results: 7376 patients underwent COLO during the study period. The median annual number of procedures performed by these hospitals was 110 (IQR, 69, 239). 930 (12.6%) procedures were emergency operations, and 3105 (42%) were laparoscopic procedures. 319 SSIs were identified including all types of SSI, and the overall SSI incidence rate was 4.32%. Several independent risk factors for COLO SSI were identified on multivariable regression, including emergency procedure status (odds ratio [OR]=1.99, 95% confidential interval [CI] 1.47-2.69), bed size over 200 beds (OR=1.51, 95% CI 1.12-2.03), ASA score 4-5 (OR=1.46, 95% CI 1.04-2.06), operation time over 75th percentile (OR=1.37, 95% CI 1.02-1.83), and obesity (BMI>30 kg/m2) (OR=1.29, 95% CI 1.03-1.63). Two factors were associated with decreased risk of SSI: age over 75years (OR=0.51, 95% CI 0.36-0.74), and laparoscopy (OR=0.69, 95% CI 0.54-0.88). The c-index of the model was 0.65.
Conclusion: Emergency procedure status was the most important risk factor for COLO SSI in our cohort of community hospitals. This variable is not included in the current NHSN methods for risk adjustment.
S. S. Lewis, None
R. W. Moehring, None
D. Sexton, Centers for Disease Control and Prevention: Grant Investigator , Grant recipient
Centers for Disease Control and Prevention Foundation: Grant Investigator , Grant recipient
UpToDate: Collaborator , Royalty Recipient
D. J. Anderson, None