Development and validation of COVID-19 Radiological Risk Score (COVID-RRS): a multivariable radiological score to estimate the in-hospital mortality risk in COVID-19 patients.

OBJECTIVE: To develop and validate in-hospital mortality risk score comprising radiological aberrances in chest computed tomography (CT) performed on admission. PATIENTS AND METHODS: Single-center, longitudinal cohort study in adult patients admitted with Coronavirus Disease 2019 (COVID-19) to our ward. Patients were followed-up during hospitalization until discharge or death. Eligibility criteria for the study comprised positive real-time reverse transcription-polymerase chain reaction test (RT-PCR) for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and ground-glass opacities in chest CT. In-hospital death was the outcome of interest. Radiological, laboratory, and clinical data were analyzed. Radiological determinants of mortality were used as variables in multivariate logistic regression analysis, and results were used to build a radiological risk score. RESULTS: 371 patients were enrolled in development and validation cohorts (181 and 190 respectively), with a total of 47 non-survivors. Univariate analysis data determined 12 predictive factors (nine risk and three protective). In multivariate analysis, we developed COVID-RRS (COVID-19 Radiological Risk Score) - a radiological score predicting in-hospital COVID-19 mortality risk comprising estimated lung involvement percentage, pleural effusion, and domination of consolidation-type changes in chest CT. Our score was superior in the prediction of COVID-19 mortality to the percentage of lung involvement alone, Chest Computed Tomography Severity Score (CTSS), and Total Severity Score (TSS) in both groups with AUC of 0.910 and 0.902, respectively (p <0.001). CONCLUSIONS: Additional imaging features independently contribute to COVID-19 mortality risk. Our model comprising lung involvement estimation, pleural effusion, and domination of consolidations performed significantly better than scores based on the extent of the changes alone. COVID-RRS is a simple, reliable, and ready-to-use tool for clinical practice.

Analysis of the effects of covid-19 on companies listed on the Warsaw stock exchange

The spread of COVID-19 has been a huge shock to the economy. Countries around the world are facing unprec-edented challenges due to the pandemic, and they have responded by locking down people’s movement and business activity and implementing stimulus packages to re-strain the devastating slowdown in economic activity. The COVID-19 outbreak has had a decisive impact on the social and purchasing habits of people all around the world. New challenges for companies have arisen as a result. The main aim of the study is to investigate the effect of COVID-19 on the reaction of the stock market and of companies (those considered to have been most significantly affected by the disruption caused by COVID-19). The paper focuses on companies listed on the WSE. The study examines the rates of return of all companies listed on the Warsaw Stock Exchange (WSE), the major indices of the Warsaw Stock Exchange and industry indices. Moreover, the authors use the case study methodology to examine the implications of COVID-19 on corporate (managerial) behaviour. A content analysis is also applied: the authors analyse all current reports and quarterly reports of the selected companies throughout the analysed period. For the purposes of further analysis, the six largest companies (accounting for almost 98% of the index as a whole) from the WIG-clothes index, which recorded the largest decline in terms of the rates of return among all sector indices on the WSE, were selected. The analysis focuses on managerial decisions in response to the COVID-19 outbreak so as to examine the challenges faced by management during the COVID-19 pandemic and the potential actions undertaken by the firms. Therefore, the authors investigated the information regarding management in the areas of financial results, investment decisions, equity decisions, dividend decisions, and other important decisions. The analysis confirmed that the COVID-19 pandemic, due to the administrative decisions and substantial number of restrictions introduced by governments, brought about temporary closures and restrictions on the scale of operations, reducing the level of employment. As a consequence, a significant decline in revenues, as well as a deterioration in financial results and the creditworthiness of most companies, could be ob-served. Our findings contribute to the limited evidence on the reaction of the stock market and companies to the challenges posed by COVID-19. © 2021, WSB University. All rights reserved.