Factors associated with the Severity of COVID-19 patients in Bac Ninh and Nghe An Provinces: A Hospital-based Case-control Study in 2022

Background: It is crucial to study characteristics and determine associated factors with the severity of COVID-19 while the pandemic has been complicated yet. We aimed to describe the characteristics and determine associated factors with the severe state of disease among COVID-19 hospitalized patients within six first months in 2022. Methods: A case – control study was conducted among 3.242 COVID-19 patients in two provincial hospitals in Bac Ninh and Nghe An from January to June 2022. Cases were defined as severe or critical COVID-19 patients and controls were COVID-19 patients who were classified into the mild group during 24-first-hour admission. We used an online research health record to collect patient’s information. Multivariable logistic regression was utilized to explore and decide associated factors with the severity of COVID-19 among participants. Results: The percentage of patients who were classified into the severe disease group at admission time was 20.0%. Respiratory symptoms (70.3%) and fatigue (30.6%) were the most common ones recorded when patients were admitted to the ward. Older age, male, pre-comorbidities such as diabetes, chronic cardiovascular or pulmonary disease increased the likelihood to have severe COVID-19 disease. D-dimer ≥ 500 ng/ml, aspartate aminotransferase enzyme (AST) > 37 U/L, the percentage of lymphocytes in blood < 20%, and C-reactive protein (CRP) ≥ 5 mg/l were identified as prognostic factors for severity within 24-first-hour admission. Two primary doses of the COVID-19 vaccine and boosted doses significantly decreased the chance to have severe COVID-19. Conclusions: Our findings highlighted that it is important to monitor patients and early diagnoses with the help of prognostic factors. Moreover, widely supplying two primary and boosted doses of the COVID-19 vaccine for people, especially for the high-risk population is necessary.