Surveillance Strategies for Tracking Sepsis Incidence and Outcomes

Sepsis is a leading cause of death and the target of intense efforts to improve recognition, management and outcomes. Accurate sepsis surveillance is essential to properly interpreting the impact of quality improvement initiatives, making meaningful comparisons across hospitals and geographic regions, and guiding future research and resource investments. However, it is challenging to reliably track sepsis incidence and outcomes because sepsis is a heterogeneous clinical syndrome without a pathologic reference standard, allowing for subjectivity and broad discretion in assigning diagnoses. Most epidemiologic studies of sepsis to date have used hospital discharge codes and have suggested dramatic increases in sepsis incidence and decreases in mortality rates over time. However, diagnosis and coding practices vary widely between hospitals and are changing over time, complicating the interpretation of absolute rates and trends. Other surveillance approaches include death records, prospective clinical registries, retrospective medical record reviews, and analyses of the usual care arms of randomized controlled trials. Each of these strategies, however, has substantial limitations. Recently, the US Centers for Disease Control and Prevention released an "Adult Sepsis Event" definition that uses objective clinical indicators of infection and organ dysfunction that can be extracted from most hospitals' electronic health record systems. Emerging data suggest that electronic health record-based clinical surveillance, such as surveillance of Adult Sepsis Event, is accurate, can be applied uniformly across diverse hospitals, and generates more credible estimates of sepsis trends than administrative data. In this review, we discuss the advantages and limitations of different sepsis surveillance strategies and consider future directions.