Designing the ASPIRE-SSI study: a multicenter, observational, prospective cohort study to assess the incidence and risk factors of surgical site and bloodstream infections caused by Staphylococcus aureus in Europe

ABSTRACT Background There is a continuing need for in-depth and updated knowledge about the epidemiology of surgical site infections (SSIs) caused by Staphylococcus aureus to support the development of effective preventive interventions. The ASPIRE-SSI study aims primarily to determine the incidence of S. aureus SSIs and postoperative bloodstream infections (BSIs) in Europe and to assess their association with patient-related, pathogen-related, and contextual risk factors. Methods ASPIRE-SSI is a prospective, multicenter, observational cohort study primarily assessing the incidence of and risk factors for S. aureus SSI and postoperative BSI in Europe. Five thousand adult surgical patients (of which two-thirds will be S. aureus carriers and one-third non-carriers) undergoing several types of surgical procedures in sites located across Europe were enrolled in the study. Data and specimens were collected from these subjects who were followed for up to 90 days following surgery to assess study outcomes. Using advanced survival analyses and regression techniques (including competing risks models), we will determine event-specific and sub-distribution hazards to assess the independent associations of these study outcomes with risk factors. Additionally, a risk prediction model will be derived to quantify the risk of developing SSI or BSI due to S. aureus . Discussion Despite the challenges, this study will provide important and contemporary information about the epidemiology of SSI and BSI (and other infections) caused by S. aureus in the current surgical population in Europe, thereby supporting the development of effective preventive interventions. Trial registration clinicaltrial.gov number NCT02935244