Application of CALL score for prediction of progression risk in patients with COVID-19 at university hospital in Turkey

Background The CALL score was developed as a predictive model for progressive disease. We aimed to validate and/or improve the performance of CALL score in our hospital settings. Methods Adult patients with polymerase chain reaction-confirmed COVID-19 were included in this retrospective observational study. Clinical and laboratory characteristics (including complete blood count, CRP, ferritin, LDH, fibrinogen, d-dimer) were obtained. ROC analysis was used for the evaluation of CALL score's performance. Cox regression analyses were performed for the selection of new parameters for improving CALL score. Results Overall, 256 patients were enrolled in the study. The median age was 54 (IQR, 22.5), 134 (52%) were women, 155 (61%) had at least one comorbidity, 60 (23%) had severe disease. The AUC value for CALL score for predicting progression to severe COVID-19 was 0.59 (95% CI 0.50-0.66). D-dimer on admission was associated with progressive disease (HR = 1.2 CI 95% 1.02-1.40), (P < .027). Conclusion The performance of the CALL score in our patient population was low compared with the original study. We found an additional parameter for predicting progressive COVID-19 disease, D-dimer, which may guide future studies to develop new scoring systems for predicting progressive disease.