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.