“…A total of 18 studies were conducted in the Asian population (7,16,20,21,23,25,26,(33)(34)(35)(36)(37)41,42,45,48,51,52) and 21 in the non-Asian population (17-19,22,24,27-32,38-40, 43,44,46,47,49-50). In terms of the source of the controls, 15 were from hosptial-based (HB) studies (16,17,20,24,25,28,30,34,35,37,41,43,45,47,51) and 24 were from population-based (PB) studies (7,18,19,(21)(22)(23)26,27,29,(31)(32)(33)36,(38)(39)…”