Visual Scoring of Chest CT at Hospital Admission Predicts Hospitalization Time and Intensive Care Admission in Covid-19

Background The extent and character of lung involvement on chest computerized tomography (CT) have a prognostic value in covid-19 but there is lack of consensus on how to assess and stage CT features. A scoring system of lung involvement in covid-19, Örebro covid-19 Scale (ÖCoS) was implemented in clinical routine on April 1 2020 in Örebro Region, Sweden. The ÖCoS-severity score measures the extent of lung involvement while ÖCoS-temporal stage characterizes the parenchymal involvement. The objective of the present study was to evaluate the ÖCoS scores in relation to clinical outcome of covid-19. Methods Population based study including data from all hospitalized patients with covid-19 in Örebro Region during March to July 2020. Chest CT scores at the time of hospital admission and ICU admission were analyzed in relation to hospital and intensive care unit (ICU) length of stay, time to ICU admission and admission to ICU or death. Findings In the 381 included patients, there was a close correlation of the ÖCoS-severity score on admittance to hospital and the hospital length of stay. The ÖCoS-severity score on hospital admittance was a strong predictor for both a severe outcome in regards to ICU admittance or death and the time to ICU admittance. On admittance to ICU, both ÖCoS-severity score and temporal stage were correlated with the ICU length of stay. Interpretation Chest CT visual scoring on admission to hospital predicts the clinical course in covid-19 pneumonia. Funding This work was supported by the Örebro Region, Sweden. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement This work was supported by the Örebro Region, Sweden. ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The Swedish Ethical Review Authority approved the study protocol and waived the informed consent requirement for this retrospective study, reference number 2020-02515. All necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes Not available according to IRB decision.