“…The included studies consists of prospective cohort studies (n = 3; Chelly et al, 2008;Hu, Xia, Jiang, Zhou, & Li, 2014;Legrand, Pihlsgård, Nordell, & Elmståhl, 2015), retrospective cohort studies (n = 3; Bhattacharya, Maung, Schuster, & Davis, 2016;Krauss et al, 2007;Y. H. Li, Song, Yu, Zhou, & Zhang, 2013), retrospective case-control studies (n = 8; Bradley, Karani, McGinn, & Wisnivesky, 2010;Coutinho, Fletcher, Bloch, & Rodrigues, 2008;Grundstrom, Guse, & Layde, 2011;Jørgensen et al, 2015;Kantayaporn, 2012;I.-F. Li et al, 2016;Mion et al, 2012;Ravindran & Kutty, 2016), matched casecontrol studies (n = 2; Hwang, Cheng, Chien, Yu, & Lin, 2015;Kuschel, Laflamme, & Möller, 2015), case-crossover studies (n = 2; Shimbo et al, 2016;Söderberg, Laflamme, & Möller, 2013), and cross-sectional studies (n = 5; Barbour et al, 2014;Ku et al, 2013;Lin & Bhattacharyya, 2014;Ylitalo & Karvonen-Gutierrez, 2016;Yuki, Asaoka, & Tsubota, 2015). Ten of the studies were conducted in the United States of America whereas the rest were conducted in Sweden (n = 3), Taiwan (n = 3), China (n = 2), Brazil (n = 1), Denmark (n = 1), India (n = 1), Japan (n = 1), and Thailand (n = 1).…”