“…Among the included studies, the diagnosis of AF was based on electrocardiograms. Three reports were from Asia, ( 16 , 24 , 25 ) 1 from Africa, ( 20 ) 7 from Europe, ( 17 – 19 , 23 , 26 , 27 , 29 ) and 8 from America ( 14 , 15 , 21 , 22 , 28 , 30 – 32 ). Apart from 4 prospective cohort studies, ( 20 , 22 , 26 , 27 ) the remaining 15 articles were designed as retrospective cohort studies ( 14 – 19 , 21 , 23 – 25 , 28 – 32 ).…”