“…14 Thirteen studies were from the USA, 12,15-26 eight from Spain, 27-34 five from Italy, 35-39 four from Korea, 40-43 three each from Turkey 44-46 and Israel, 47-49 two each from the Netherlands 50,51 and the UK, 52,53 and single studies from Denmark, 54 Germany, 55 Norway, 56 and Australia. 57 Of the 46 studies 34 were retrospective in design and only three of these studies were case controlled. 16,36,49 Whilst a few studies focused on specific patient groups, most included all adult patients.…”