Epidemiology of Sepsis-associated Acute Kidney Injury in Beijing, China : a descriptive analysis

Background: Sepsis is the most common contributing factor towards development of acute kidney injury (AKI), which is strongly associated to poor prognostic outcomes. There are numerous epidemiological studies about sepsis-associated acute kidney injury (S-AKI), however current literature is limited with the majority of studies being conducted only in the intensive care unit (ICU) setting. The aim of this study was to assess the epidemiology of S-AKI in all hospitalized in-patients. Methods: This was a retrospective population-based study using a large regional population database in Beijing city from January, 2005 to December, 2017. It included patients with S-AKI. Patients with pre-existing end-stage kidney disease (ESKD), previous history of kidney transplantation, or being pregnant were excluded. Patients’ demographic characteristics, incidence, risk factors and outcomes of S-AKI were analyzed. The differences between different time periods, different levels of hospitals, and types of the hospitals (i.e. traditional Chinese medicine hospitals (TCMHs) and Western medicine hospitals (WMHs)) were also compared using Mann-Whitney U test. Results: A total of 19,579 patients were included. The overall incidence of S-AKI in all in-patients was 48.1%. The risk factors for AKI included: age (P < 0.001), male (P < 0.001), treatment in a level-II hospital (P < 0.001) and so on. The overall mortality rate in this cohort was 55%. The risk factors for mortality included: age (P < 0.001), female (P < 0.001), pre-existing chronic kidney disease (CKD) (P = 0.023) and so on. The incidence of S-AKI increased over time, but the mortality rate did not. Compared with level-II hospitals, the incidence of S-AKI was similar in tertiary hospitals, but the mortality rate was significantly higher.Although patients treated in TCMHs had a shorter hospital stay and a lower cost of care, this cohort had a higher mortality rate when compared with patients treated in WMHs. Conclusions: AKI is a common complication in all hospitalized patients with sepsis, and its incidence increases over time, especially when ICU admission is required. Exploring interventional strategies to address modifiable risk factors will be important to reduce incidence and mortality of S-AKI.