The epidemiology of risk factors and short and long-term outcome in the Swedish intensive care cohort

Abstract: Dissertation presented at Uppsala University to be publicly examined on Zoom: https://uu-se.zoom.us/j/7214327760, Tuesday, 11 May 2021 at 13:00 for the degree of Licentiate of Philosophy (Faculty of Medicine). The examination will be conducted in English and Swedish. Chairman of the Examining committee: Professor Karl Michaëlsson (Medical epidemiology, Department of Surgical Sciences, Uppsala University, Uppsala) Abstract Ahlström, B. 2021. The epidemiology of risk factors and short- and long-term out-come in the Swedish intensive care cohort. 76 pp.  Severe sepsis and septic shock, linked to persistent organ dysfunctions, have poor short- and long-term mortality outcomes. These conditions also adversely affect health-related quality of life. After intensive care with severe sepsis and septic shock, memory and other cognitive functions have shown deterioration. In addition, there are indications of an increased risk of dementia. Yet, whether severe sepsis and septic shock are independently linked to dementia or dementia development is linked to more general severe illness remains unclear. In the Swedish intensive care cohort we compared 16 115 one-year sepsis survivors without previous dementia to 194 219 patients (controls) admitted to intensive care for other reasons using a Cox proportional hazards model. The crude risk of dementia was increased in the severe sepsis and septic shock group. However, after adjustment for demographics, comorbidities and factors reflecting the severity of acute illness, severe sepsis and septic shock was found not to be a significant risk factor of incident dementia with a haz-ard ratio of 1.01 (95% confidence interval 0.91-1.11). Thus, we concluded that although the incidence of dementia is high after intensive care, severe sepsis or septic shock is not causative.  Coronavirus disease 2019 (COVID-19) has put a tremendous strain on the healthcare system in general and intensive care, in particular, since its emergence in Wuhan, China, in late 2019. Risk factors of ICU admission and mortality from COVID-19 were reported early during the pandemic, but only as univariate variables. Under the hypothesis that there are several independent risk factors of critical COVID-19, we used statistical models to explore demographic characteristics and comorbidi-ties in the first 1 981 ICU-admitted patients with COVID-19 in Sweden. On the risk of ICU admission, we also included matched population controls in a 1:4 ratio. Hypertension, type 2 diabetes mellitus, chronic renal failure, asthma, obesity, solid organ transplant recipient and immunosuppressant medications were independent risk factors of ICU admission. Oral anticoagulants were associated with a protective effect. Stroke, asthma, chronic obstructive pulmonary disease and treatment with renin-angiotensin-aldosterone inhibitors were independent risk factors of ICU mortality. Treatment with statins was protective. Our findings suggest that there are several independent risk factors of ICU admission and ICU mortality in COVID-19.Björn Ahlström, Department of Surgical Sciences, Anaesthesiology and Intensive Care, Uppsala University, SE-75185 Uppsala, Sweden  and  Centre of clinical research, Region Dalarna, SE-79182 Falun, Sweden.