3.3 Meta-analysis for Severity Outcome:
The current meta-analysis results indicated that NOAF in the COVID-19 was associated with an increased incidence of severe disease compared with COVID-19 patients without any history of atrial fibrillation (OR= 4.78, 95% CI 3.75 to 6.09). The outcome had high associated heterogeneity (I 2 = 82%). The result was pooled from 15 studies, comprising 54,051 COVID-19 patients (Figure 3 A).
Similarly, our analysis reported that NOAF in COVID-19 patients was associated with an increased incidence of severe disease compared with COVID-19 patients with a history of pre-existing atrial fibrillation (OR= 2.75, 95% CI 2.10 to 3.59). The outcome had moderate associated heterogeneity (I 2 = 41%). The result was pooled from 7 studies, comprising 2625 COVID-19 patients (Figure 3 B).