“…Studies included in this review originated from 5 continents. Sixteen (35%) studies were conducted in the United States, 15-30 7 (15%) in Canada, 31-37 6 (13%) in Germany, 38-43 4 (9%) in Australia, [44][45][46][47] 2 (4%) in the Netherlands, 48,49 2 (4%) in Switzerland, 50,51 2 (4%) in Finland, 52,53 2 (4%) in Japan, 54,55 1 (2%) in Brazil, 56 1 (2%) in India, 57 and 1 (2%) in Norway. 58 In addition, 2 (4%) studies were conducted in centers located both in Canada and the United States.…”