“…Among the different statistical indices, OR was the most frequently used (29 studies) [4,5,12,21,22,[24][25][26][27][32][33][34]40,[42][43][44]47,48,50,52,58,59,[62][63][64]70,74,77,78], while RR and HR were used in 10 [15,18,23,39,45,48,56,57,72,73] and 6 studies [51,52,60,65,66,77], respectively. A minority of meta-analyses investigated pooled differences of cardiac biomarkers between severe vs non-severe disease or survivors vs non survivors (Table 1).…”