External validity of the Society of Thoracic Surgeons risk stratification tool for deep sternal wound infection after cardiac surgery in a UK population

OBJECTIVES Deep sternal wound infection (DSWI) is a devastating complication of cardiac surgery, with a historical incidence of 0.4–5%. Predicting which patients are at higher risk of infection may help instituting various preventive measures. Risk calculations for mortality have been used as surrogates to estimate the risk of deep sternal wound infection, with limited success. The Society of Thoracic Surgeons (STS) 2008 Risk Calculator modelled the risk of DSWI for cardiac surgical patients, but it has not been validated since its publication. We sought to assess the external validity of the STS-estimated risk of DSWI in a United Kingdom (UK) population.