“…Six studies were conducted in the United States [ 43 , 45 , [47] , [48] , [49] , [50] ], one each in Japan, the Netherlands and Germany [ 30 , 46 , 51 ], and one in six European countries [ 51 ]. Of the articles, seven consisted of secondary data analysis [ 30 , 43 , 45 , 47 , 48 , 50 , 51 ] and the other two were primary studies [ 46 , 49 ]. All studies used a cross-sectional study design [ 30 , 43 , [45] , [46] , [47] , [48] , [49] , [50] ], with the exception of one which was a prospective cohort study [ 51 ].…”