[1] ROYAL VICTORIA INFIRM,DEPT CARDIOL,NEWCASTLE TYNE NE1 4LP,TYNE & WEAR,ENGLAND
[2] UNIV NEWCASTLE UPON TYNE,DEPT CLIN BIOCHEM,NEWCASTLE TYNE NE1 7RU,TYNE & WEAR,ENGLAND
[3] UNIV OXFORD,DEPT PUBL HLTH & PRIMARY CARE,OXFORD OX2 6HE,ENGLAND
[4] UNIV NEWCASTLE UPON TYNE,DEPT MED,NEWCASTLE TYNE NE1 7RU,TYNE & WEAR,ENGLAND