“…Some studies took care to ascribe ethnic group using self or observer assigned census categories [ 13 , 17 , 27 ], whereas others based it upon place of birth [ 12 , 30 , 32 , 33 ]. Ethnicity was more variously defined in studies using data from medical records and for some studies ethnicity was based on South Asian names [ 16 ], place of birth [ 14 , 15 , 18 ], or country of origin [ 21 , 22 ].…”