[1] UCL, Sch Publ Policy, Hlth Policy & Hlth Serv Res Unit, London WC1H 9EZ, England
[2] Univ Glasgow, Dept Human Nutr, Glasgow G31 2ER, Lanark, Scotland
[3] Northumbria Univ, Social Welfare Res Unit, Newcastle Upon Tyne NE7 7XA, Tyne & Wear, England
[4] Univ Manchester, Dept Accounting, Manchester M13 9PL, Lancs, England