“…Of the 21 studies included, five were RCTs (Herfjord et al, 2014;Lawler et al, 2019;Lenze et al, 2012Lenze et al, , 2019Parker et al, 2015) and 16 were observational cohort studies (Abrahamsen et al, 2014(Abrahamsen et al, , 2016Chen et al, 2002;Dejong et al, 2009;Fiorini et al, 2013;Galizia et al, 2018;Gustavson et al, 2019;Hong et al, 2019;Jette et al, 2004;Jung et al, 2016;Leung et al, 2016;Mallinson et al, 2014;Millar et al, 2017;Morita et al, 2018;O'Brien & Zhang, 2018;Zhang et al, 2019). Eleven studies were conducted in the United States (Chen et al, 2002;Dejong et al, 2009;Gustavson et al, 2019;Hong et al, 2019;Jette et al, 2004;Jung et al, 2016;Lenze et al, 2012Lenze et al, , 2019Mallinson et al, 2014;O'Brien & Zhang, 2018;Zhang et al, 2019), two in Australia (Lawler et al, 2019;Parker et al, 2015), three in Norway (Abrahamsen et al, 2014(Abrahamsen et al, , 2016Herfjord et al, 2014), two in Italy (Fiorini et al, 2013;Galizia et al, 2018), and the remainder were conducted in Canada (Leung et...…”