“…In total, 17 of the 25 studies were conducted in North America [17-22, 24-27,29,31,34,37-40], three in Europe [23,30,35], three in China [16,28,32], and two in Iran [33,36]. Thirteen of the 25 studies did not report racial ethnicity [16,20,21,23,24,26,28,30,32,33,35,36,38]. The sample size ranged from 38 [24] to 3462 [19], and the average patient age was between 65 [36] and 82 years [27,30].…”