Intensive care unit admission and associated factors in patients hospitalised for COVID-19: A national retrospective cohort study in Iran

Abstract

Objectives This study aimed to determine factors associated with intensive care unit (ICU) admission in patients hospitalised due to COVID-19.Design Retrospective cohort.Setting Confirmed hospitalised patients from all over Iran were considered for the study.Participants All patients with COVID-19 admitted to the hospital from March 2020 to May 2021 were included by census. ICU admission was defined by the following criteria: (1) admission to the ICU ward; (2) level of consciousness (loss of consciousness); and (3) use of invasive ventilation.Methods This is a secondary data analysis from the Medical Care Monitoring Center. The association between different variables and ICU admission was assessed by forward Logistic regression and restricted cubic spline method.Results The mean age of the 1 469 620 patients with COVID-19 was 54.49±20.58 years old, and 51.32% of the patients were male. The prevalence of ICU admission was 19.19%. The mean age of patients admitted to the ICU was higher than that of other hospitalised patients (62.49±19.73 vs 52.59±20.31 years). The prevalence of ICU admission was 17.17% in the first, 21.52% in the second, 19.72% in the third, 21.43 in the fourth and 17.4% in the fifth wave. In the multivariable model, age groups, sex, waves of the epidemic, comorbidities and saturation of peripheral oxygen (SpO2) <93% and acute respiratory distress syndrome (ARDS) were associated with an increased odds of ICU admission. The OR for ICU admission indicates a significant protective effect at a young age and then a significant risk factor for admission to the ICU ward at an old age.Conclusions Men, older adults, people who suffer from ARDS, patients with SpO2 levels of less than 93% and cases with comorbidities had the highest odds of ICU admission. Therefore, these groups should take all necessary precautions to avoid contracting COVID-19.