Importance: Despite the large health burden, reliable data on sepsis epidemiology are lacking; studies using International Statistical Classification of Diseases and Related Health Problems (ICD)–coded hospital discharge diagnosis for sepsis identification suffer from limited sensitivity. Also, ICD data do not allow investigation of underlying pathogens and antimicrobial resistance.Objectives: To generate reliable epidemiological estimates by linking data from a population-based database to a reference standard of clinical medical record review.Design, Setting, and Participants: This was a retrospective, observational cohort study using a population-based administrative database including all acute care hospitals of the Scania region in Sweden in 2019 and 2020 to identify hospital-treated sepsis cases by ICD codes. From this database, clinical medical records were also selected for review within 6 strata defined by ICD discharge diagnosis (both with and without sepsis diagnosis). Data were analyzed from April to October 2022.Main outcomes and measures: Hospital and population incidences of sepsis, case fatality, antimicrobial resistance, and temporal dynamics due to COVID-19 were assessed, as well as validity of ICD-10 case identification methods compared with the reference standard of clinical medical record review.Results: Out of 295 531 hospitalizations in 2019 in the Scania region of Sweden, 997 patient medical records were reviewed, among which 457 had sepsis according to clinical criteria. Of the patients with clinical sepsis, 232 (51%) were female, and 357 (78%) had at least 1 comorbidity. The median (IQR) age of the cohort was 76 (67-85) years. The incidence of sepsis in hospitalized patients according to the Third International Consensus Definitions for Sepsis and Septic Shock (Sepsis-3) criteria in 2019 was 4.1% (95% CI, 3.6-4.5) by medical record review. This corresponds to an annual incidence rate of 747 (95% CI, 663-832) patients with sepsis per 100 000 population. No significant increase in sepsis during the COVID-19 pandemic nor a decrease in sepsis incidence when excluding COVID-19 sepsis was observed. Few sepsis cases caused by pathogens with antimicrobial resistance were found. The validity of ICD-10–based case identification in administrative data was low.Conclusions and Relevance: In this cohort study of sepsis epidemiology, sepsis was a considerable burden to public health in Sweden. Supplying administrative data with information from clinical medical records can help to generate reliable data on sepsis epidemiology.

Early administration of antibiotics is associated with better survival in sepsis, thus screening and early detection for sepsis is of clinical importance. Current risk stratification scores used for bedside detection of sepsis, for example Quick Sequential Organ Failure Assessment (qSOFA) and National Early Warning Score 2 (NEWS2), are primarily validated for death and intensive care. The primary aim of this study was to compare the diagnostic accuracy of qSOFA and NEWS2 for a composite outcome of sepsis with organ dysfunction, infection-related mortality within <72 h, or intensive care due to an infection. Retrospective analysis of data from two prospective, observational, multicentre, convenience trials of sepsis biomarkers at emergency departments were performed. Cohort A consisted of 526 patients with a diagnosed infection, 288 with the composite outcome. Cohort B consisted of 645 patients, of whom 269 had a diagnosed infection and 191 experienced the composite outcome. In Cohort A and B, NEWS2 had significantly higher area under receiver operating characteristic curve (AUC), 0.80 (95% CI 0.75–0.83) and 0.70 (95% CI 0.65–0.74), than qSOFA, AUC 0.70 (95% CI 0.66–0.75) and 0.62 (95% CI 0.57–0.67) p < 0.01 and, p = 0.02, respectively for the composite outcome. NEWS2 was superior to qSOFA for screening for sepsis with organ dysfunction, infection-related mortality or intensive care due to an infection both among infected patients and among undifferentiated patients at emergency departments.

Background: Although sepsis is a major health problem, data on sepsis epidemiology are scarce. The aim of this study was to assess the incidence of sepsis, based on clinical findings in all adult patients treated with intravenous antibiotic in all parts of all hospitals in an entire population. Methods: A retrospective chart review of patients ≥18 years, living in two regions in Sweden, who were started on an intravenous antibiotic therapy on four dates, evenly distributed over the year of 2015. The main outcome was the incidence of sepsis with organ dysfunction. The mean population ≥18 years at 2015 in the regions was 1,275,753. 563 patients living in the regions were started on intravenous antibiotic treatment on the dates of the survey. Patients who had on-going intravenous antibiotic therapy preceding the inclusion dates were excluded, if sepsis was already present. Results: 482 patients were included in the study; 339 had a diagnosed infection, of those 96 had severe sepsis according to the 1991/2001 sepsis definitions, and 109 had sepsis according to the sepsis-3. This is equivalent to an annual incidence of traditional severe sepsis of 687/100,000 persons (95% CI 549-824) or according to the sepsis-3 definition of 780/100,000 persons (95% CI 633-926). 74 patients had sepsis according to both definitions. Conclusions: The incidence of sepsis with organ dysfunction is higher than most previous estimates independent of definition. The inclusion of all in-patients started on intravenous antibiotic treatment of sepsis in a population makes an accurate assessment of sepsis incidence possible.

One can falsely assume that it is well known that bacteremia is associated with higher mortality in sepsis. Only a handful of studies specifically focus on the comparison of culture-negative and culture-positive sepsis with different conclusions depending on study design. The aim of this study was to describe outcome for critically ill patients with either culture-positive or -negative sepsis in a clinical review. We also aimed to identify subphenotypes of sepsis with culture status included as candidate clinical variables. Out of 784 patients treated in intensive care with a sepsis diagnosis, blood cultures were missing in 140 excluded patients and 95 excluded patients did not fulfill a sepsis diagnosis. Of 549 included patients, 295 (54%) had bacteremia, 90 (16%) were non-bacteremic but with relevant pathogens detected and in 164 (30%) no relevant pathogen was detected. After adjusting for confounders, 90-day mortality was higher in bacteremic patients, 47%, than in non-bacteremic patients, 36%, p = 0.04. We identified 8 subphenotypes, with different mortality rates, where pathogen detection in microbial samples were important for subphenotype distinction and outcome. In conclusion, bacteremic patients had higher mortality than their non-bacteremic counter-parts and bacteremia is more common in sepsis when studied in a clinical review. For reducing population heterogeneity and improve the outcome of trials and treatment for sepsis, distinction of subphenotypes might be useful and pathogen detection an important factor.

Background and aims: Neutrophil-derived heparin binding protein (HBP; also known as azurocidin or CAP-37) is a key player in bacterial sepsis and a promising biomarker in severe infections. The aims of this study were to assess whether HBP is involved in the pathophysiology of COVID-19 and, if so, whether it can be used to predict severe disease preferably using a point-of-care test. Methods: This was a prospective convenience sample study of biomarkers in patients admitted to Skåne University hospital in Sweden with a confirmed COVID-19 diagnosis. Plasma samples and clinical data were collected within 72h after admission, during hospital stay and at discharge. Plasma HBP concentrations samples were measured both with enzyme-linked immunosorbent assay (ELISA) and with a novel dry immunofluorescence analyzer (Joinstar) point-of-care test. Results: Thirty-five COVID-19 patients were enrolled in the study. Twenty-nine patients had blood samples taken within 72h after admission. We compared the highest HBP value taken within 72h after admission in patients who eventually developed organ dysfunction (n = 23) compared to those who did not (n = 6), and found that HBP was significantly elevated in those who developed organ dysfunction (25.0 ng/mL (interquartile range (IQR) 16.6–48.5) vs 10.6 ng/mL (IQR 4.8–21.7 ng/mL), p = 0.03). Point-of-care test measurements correlated well with ELISA measurements (R = 0.83). HBP measured by the POC device predicted development of COVID-induced organ dysfunction with an AUC of 0.88 (95% confidence interval (CI) 0.70–1.0). Conclusions: HBP is elevated prior to onset of organ dysfunction in patients with severe COVID-19 using a newly developed point-of-care test and hence HBP could be used in a clinical setting as a prognostic marker in COVID-19.

OBJECTIVES: The Sepsis-3 definition states the clinical criteria for sepsis but lacks clear definitions of the underlying infection. To address the lack of applicable definitions of infection for sepsis research, we propose new criteria, termed the Linder-Mellhammar criteria of infection (LMCI). The aim of this study was to validate these new infection criteria. DESIGN: A multicenter cohort study of patients with suspected infection who were admitted to emergency departments or ICUs. Data were collected from medical records and from study investigators. SETTING: Four academic hospitals in Sweden, Switzerland, the Netherlands, and Germany. PATIENTS: A total of 934 adult patients with suspected infection or suspected sepsis. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Agreement of infection site classification was measured using the LMCI with Cohen κ coefficient, compared with the Calandra and Cohen definitions of infection and diagnosis on hospital discharge as references. In one of the cohorts, comparisons were also made to adjudications by an expert panel. A subset of patients was assessed for interobserver agreement. MEASUREMENTS AND MAIN RESULTS: The precision of the LMCI varied according to the applied reference. LMCI performed better than the Calandra and Cohen definitions (κ = 0.62 [95% CI, 0.59–0.65] vs κ = 0.43 [95% CI, 0.39–0.47], respectively) and the diagnosis on hospital discharge (κ = 0.57 [95% CI, 0.53–0.61] vs κ = 0.43 [95% CI, 0.39–0.47], respectively). The interobserver agreement for the LMCI was evaluated in 91 patients, with agreement in 77%, κ = 0.72 (95% CI, 0.60–0.85). When tested with adjudication as the gold standard, the LMCI still outperformed the Calandra and Cohen definitions (κ = 0.65 [95% CI, 0.60–0.70] vs κ = 0.29 [95% CI, 0.24–0.33], respectively). CONCLUSIONS: The LMCI is useful criterion of infection that is intended for sepsis research, in and outside of the ICU. Useful criteria for infection have the potential to facilitate more comparable sepsis research and exclude sepsis mimics from clinical studies, thus improving and simplifying sepsis research.