Blood culture positive sepsis in England, 2017–2018: epidemiological assessment of the commissioning for quality and innovation (CQUIN) sepsis indicator

Background: Sepsis remains a significant clinical and public health concern, necessitating timely identification and targeted management for improved patient outcomes. This study describes the epidemiology of sepsis in emergency department attendees across England by analysing a unique multi-site linked dataset to inform approaches to strengthen surveillance and improve our understanding of clinical outcomes. Methods: An existent study dataset was utilised comprising a sample of paediatric and adult emergency department admissions screened for community-onset sepsis in the Commissioning for Quality and Innovation (CQUIN) program in the 2017/18 financial year linked to Hospital Episode Statistics and Office for National Statistics death registrations. This dataset was linked to the United Kingdom Health Security Agency’s Second-Generation Surveillance System for microbiological data. Descriptive analyses were conducted to characterise sepsis screen positives and negatives in CQUIN, including demographic characteristics, clinical presentations, microbiological profiles, and clinical outcomes. Results: Of the 4,027 sepsis-screened emergency admissions included, 2,454 (60.9%) were sepsis screen positive under the CQUIN indicator. Only 11.2% (453/4,027) had a positive blood culture within 2 days of hospital admission. Blood culture positivity rates were 15.2% (373/2,454) and 5.1% (80/1,573) for sepsis screen positive and negative in CQUIN, respectively. Monomicrobial episodes predominated (86.5%), with Escherichia coli and Staphylococcus species being the most commonly isolated bacteria. The study showed a case fatality rate of 17.1% (420/2,454) for sepsis screen positive in CQUIN but revealed no significant difference in all-cause 30-day mortality between sepsis screen positives in CQUIN with and without positive blood cultures. Sepsis screen positives in CQUIN with a focal site of infection code were more likely to have positive blood cultures, except for respiratory infections. Conclusions: This study provides novel insights into the epidemiology of sepsis screening in emergency departments across England, highlighting variability in blood culture positivity rates and microbial profiles. The findings underscore the importance of enhanced surveillance strategies, optimised screening protocols, tailored antimicrobial stewardship practices, and quality improvement initiatives to optimise sepsis management and outcomes. Systemic approaches are needed to address knowledge gaps and inform evidence-based interventions for sepsis care.