“… 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 The process of study selection is summarised in Supplementary Figure 1 using the PRISMAflowchart. Sixteen studies reported the association of CAR with COVID‐19 outcomes, 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 four studies included FAR, 28 , 29 , 30 , 31 and three studies included both CAR and FAR. 32 , 33 , 34 Table 1 outlines the study characteristics of the included articles, while Table 2 summarises the optimal cut‐off, the area under the curve (AUC), sensitivity, and specificity of CAR and FAR for predicting COVID‐19 mortality and severity.…”