Charlson comorbidity index to predict 28-day mortality in critically ill COVID-19 patients

BACKGROUND Severe COVID-19 patients may become critically ill and require treatment in the intensive care unit (ICU). As intensive care resources are limited, mortality predictors should be used to guide resource allocation. This study aimed to validate the Charlson comorbidity index (CCI) as the mortality predictor of critical COVID-19 patients in the ICU. METHODS A retrospective cohort study was done in adult patients admitted to the ICU with severe COVID-19 at Cipto Mangunkusumo Hospital and Universitas Indonesia Hospital from March to August 2020. We extracted the subject's CCI score from the medical records and the 28-day mortality after ICU admission. The CCI score was validated by the Hosmer-Lemeshow calibration test, determination of area under the curve (AUC), and optimal cut-off point for the critical patients in the ICU. We used the chi-square test to examine the association of comorbidities with mortality. RESULTS Mortality was higher in CCI scores >4 (odds ratio [OR]: 8.83; 95% confidence interval [CI] = 1.81-43.01). The CCI score had moderate discrimination ability (AUC 76.1%; 95% CI = 0.661-0.881). Chronic kidney disease (CKD) (OR: 18.00, 95% CI = 2.19-147.51), congestive heart failure (CHF) (OR: 4.25, 95% CI = 1.23-14.75), and uncontrolled diabetes mellitus (DM) (OR: 18.429, 95% CI = 2.19-155.21) increased the risk of 28-day mortality. CONCLUSIONS The CCI score could predict the 28-day mortality of critical COVID-19 patients. The coexistence of CKD, CHF, DM, peripheral vascular disease, and peptic ulcer in COVID-19 patients should be considered for patient management.