“…The main characteristics of all 40 included studies are presented in Table 2. Twenty-five studies were performed in the US [36, 37, 39, 45-52, 55, 56, 58-60, 62, 63, 65, 67, 69-73], two each in Australia [34,54], Canada [41,42], the Netherlands [38,44], Spain [40,64], and the UK [35,66], and one each in Germany [68], Saudi Arabia [53], Singapore [57], Switzerland [61], and Qatar [43]. Thirty-six studies were single-center studies, and four studies were performed in more than one hospital [50,65,66,69].…”