Rates of severe sepsis are higher than estimated in most studies, according to a retrospective review of patients on IV antibiotics in Sweden.
“The incidence of traditional severe sepsis was higher than in most preceding studies, which is not surprising since many studies are based on discharge diagnoses and have proven to fail to register many episodes,” Lisa Mellhammar, MD, a clinical researcher at Lund University, and colleagues wrote in Open Forum Infectious Diseases. “Also, earlier studies have been restricted to certain wards or EDs. In this study, we screened all adult patients, who were started on IV antibiotic treatment, in all parts of all hospitals in two entire regions, and therefore identifying all both community-acquired and nosocomial sepsis cases.”
Due to the complexity of sepsis and its interactions with other diseases, it is often difficult to diagnose and to estimate its incidence, the researchers said. Mellhammar and colleagues sought to form a more complete picture of sepsis incidence by analyzing all patients on IV antibiotics within the regions of Skåne and Halland in southern Sweden.
The researchers assessed how the recent change in criteria for sepsis has affected epidemiological estimates. According to 1991/2001 guidelines, traditional severe sepsis is defined as hypotension, hypoperfusion or organ dysfunction induced by sepsis. The new definition — designated sepsis-3 — defines sepsis as organ dysfunction, “characterized by a rise in Sequential (Sepsis-related) Organ Failure Assessment (SOFA) score [of at least] 2, due to a dysregulated host response to infection” and does not distinguish between sepsis and severe sepsis.
Using a national database called the anti-infection tool, the researchers reviewed the charts of all patients aged 18 years or older living Skåne and Halland who were started on IV antibiotic therapy in a hospital on Jan. 12, April 13, July 13, or Oct. 12, 2015.
Of the 563 patients who started IV treatment on the dates of the survey, 482 patients met the study’s inclusion criteria. Of 339 patients with a diagnosed infection, 28.3% had severe sepsis, according to the older sepsis guidelines, which is equivalent to an annual incidence of traditional severe sepsis of 687 cases per 100,000 persons (95% CI, 549-824).
According to the sepsis-3 definition, 32.3% of the 339 patients had sepsis, which is equivalent to an annual incidence of 780 cases per 100,000 persons (95% CI, 633-926). Seventy-four (21.8%) patients had sepsis according to both definitions.
Researchers noted that, although the sepsis-3 definition will identify a slightly different cohort of patients, the change in definition itself will impact the overall epidemiological estimates of sepsis incidence less than the differences in methodologies across various incidence studies.
They emphasized that, regardless of its definition, sepsis is still a concern.
“Approximately one out of four of these patients receiving IV antibiotics had or developed organ dysfunction,” they wrote. “The burden of antibiotic resistance is still relatively low in Sweden indicating that the incidence of traditional severe sepsis and sepsis-3 may be higher in other parts of the world and with a growing antimicrobial resistance it will likely increase.”– by Sarah Kennedy
Disclosure: The researchers report no relevant financial disclosures.