“…Of the 30 studies included in these analyses, 11 (11,13,22,26,37,41,45,52,53,56,63) did not provide racial or ethnic information, 16 were mainly Caucasian (4)(5)(6)14,21,(23)(24)(25)(30)(31)(32)36,40,51,57,58), one consisted mainly of black Africans (48), and two consisted of Asians (19,20). There was insufficient data to determine whether racial or ethnic differences exist.…”