The COVID-19 Assessment for Survival at Admission (CASA) Index: A 12 Months Observational Study

• Main Authors: Gianluca Bagnato, Daniela La Rosa, Carmelo Ioppolo, Alberta De Gaetano, Marianna Chiappalone, Natalia Zirilli, Valeria Viapiana, Maria Concetta Tringali, Simona Tomeo, Caterina Oriana Aragona, Francesca Napoli, Sara Lillo, Natasha Irrera, William Neal Roberts, Egidio Imbalzano, Antonio Micari, Elvira Ventura Spagnolo, Giovanni Squadrito, Sebastiano Gangemi, Antonio Giovanni Versace
• Format: Article
• Language: English
• Published: Frontiers Media S.A. 2021-09-01
• Series: Frontiers in Medicine
• Subjects: COVID-19; outcome research; mortality risk; stratification index; systemic score
• Online Access: https://www.frontiersin.org/articles/10.3389/fmed.2021.719976/full

Objective: Coronavirus disease 2019 (COVID-19) is a disease with a high rate of progression to critical illness. However, the stratification of patients at risk of mortality is not well defined. In this study, we aimed to define a mortality risk index to allocate patients to the appropriate intensity of care.Methods: This is a 12 months observational longitudinal study designed to develop and validate a pragmatic mortality risk score to stratify COVID-19 patients aged ≥18 years and admitted to hospital between March 2020 and March 2021. Main outcome was in-hospital mortality.Results: 244 patients were included in the study (mortality rate 29.9%). The Covid-19 Assessment for Survival at Admission (CASA) index included seven variables readily available at admission: respiratory rate, troponin, albumin, CKD-EPI, white blood cell count, D-dimer, Pa02/Fi02. The CASA index showed high discrimination for mortality with an AUC of 0.91 (sensitivity 98.6%; specificity 69%) and a better performance compared to SOFA (AUC = 0.76), age (AUC = 0.76) and 4C mortality (AUC = 0.82). The cut-off identified (11.994) for CASA index showed a negative predictive value of 99.16% and a positive predictive value of 57.58%.Conclusions: A quick and readily available index has been identified to help clinicians stratify COVID-19 patients according to the appropriate intensity of care and minimize hospital admission to patients at high risk of mortality.