Comparison of different prognostic scores in estimating short- and long-term mortality in COVID-19 patients above 60 years old in a university hospital in Belgium

Key summary points Aim Determining among 6 different scores which one most accurately predicted short-and long-term mortality in hospitalized COVID-19 patients above 60 years old. Findings Among 6 different prognostic scales, the 4C Mortality Score (4CMS) was the best to predict intrahospital mortality and mortality at 30 days and 6 months. To predict 12-month mortality, the Charlson Comorbidity Index (CCI) had the best performance. Message This study reflects the importance of considering comorbidities for short and long-term mortality after COVID-19. Background and objectives Multiple scoring systems were used for risk stratification in COVID-19 patients. The objective was to determine among 6 scores which performed the best in predicting short-and long-term mortality in hospitalized COVID-19 patients ≥ 60 years. Methods An observational, retrospective cohort study conducted between 21/10/2020 and 20/01/2021. 6 scores were calculated (Clinical Frailty Scale (CFS), Charlson Comorbidity Index (CCI), 4C Mortality Score (4CMS), NEWS score (NEWS), quick-SOFA score (qSOFA), and Quick COVID-19 Severity Index (qCSI)). We included unvaccinated hospitalized patients with COVID-19 ≥ 60 years old in Brugmann hospital, detected by PCR and/or suggestive CT thorax images. Old and nosocomial infections, and patients admitted immediately at the intensive care unit were excluded. Results 199 patients were included, mean age was 76.2 years (60–99). 47.2% were female. 56 patients (28%) died within 1 year after the first day of hospitalization. The 4CMS predicted the best intrahospital, 30 days and 6 months mortality, with area under the ROC curve (AUROC) 0.695 (0.58–0.81), 0.76 (0.65–0.86) and 0.72 (0.63–0.82) respectively. The CCI came right after with respectively AUROC of 0.69 (0.59–0.79), 0.74 (0.65–0.83) and 0.71 (0.64–0.8). To predict mortality at 12 months after hospitalization, the CCI had the highest AUROC with 0.77 (0.69–0.85), before the 4CMS with 0.69 (0.60–0.79). Discussion Among 6 scores, the 4CMS was the best to predict intrahospital, 30-day and 6-month mortality. To predict mortality at 12 months, CCI had the best performance before 4CMS. This reflects the importance of considering comorbidities for short- and long-term mortality after COVID 19. Registration This study was approved by the ethical committee of Brugmann University Hospital (reference CE 2020/228).