Surgical Site Infection Measure for National Reporting

• Activity Number: 140
• Type: Contributed
• Date/Time: Monday, August 1, 2011 : 8:30 AM to 10:20 AM
• Sponsor: Section on Statistics in Epidemiology
• Author(s): Yi Mu*+ and Jonathan Edwards and Teresa C. Horan and Scott Fridkin
• Companies: Centers for Disease Control and Prevention and Centers for Disease Control and Prevention and Centers for Disease Control and Prevention and Centers for Disease Control and Prevention
• Keywords: Quality ; hospital ; hierarchical ; surgical site infection ; risk adjusment

Abstract

The CDC's National Healthcare Safety Network (NHSN), used by CDC and its partners for surveillance of healthcare-associated infections, provides a Standard Infection Ratio (SIR) to participating hospitals to help promote healthcare quality improvement. The SIR is the ratio of the observed surgical site infection (SSI) incidence divided by the expected SSI incidence. To calculate the expected SSI incidence for a hospital, the probability of SSI for each surgical patient are summed; the individual probabilities can be calculated by using procedure-specific risk-adjusted models. Procedure-specific risk-adjusted models were derived using 2006-2008 NHSN data, which contained 62,782 colon surgeries and 54,877 abdominal hysterectomies. Models for procedure-specific risk adjustment were developed using step-wise logistic regression and later validated using bootstrap sampling. The reliability-adjusted SIR was obtained by using hierarchical modeling techniques to shrink the observed SSI incidence toward the expected incidence given hospital procedure volume and risk factors. The resulting adjusted SIRs are more comparable and stable to better measure quality performance.