“…Chart 1 shows the selected studies according to country, year, databases, and title. Of the 21 publications, nine studies (42%) were conducted in the United States ( 13 – 21 ) , four (19%) in Brazil ( 22 , 23 , 24 , 25 ) , two (9%) in Canada ( 26 , 27 ) . Countries such as Mexico ( 28 ) , Iran ( 29 ) , Portugal ( 30 ) , Finland ( 31 ) , Sweden ( 32 ) , and the United Kingdom ( 33 ) presented only one (5%) study each.…”