1. University of Liverpool; Division of Primary Care; Liverpool UK L69 3GB
2. Garswood Surgery; Station Road Garswood St. Helens Merseyside UK WND 0SD
3. Peking University; Institute of Population Research; Yiheyuanroad 5 Haidian District Beijing China 100871
4. University of Liverpool; Health Inequalities and the Social Determinants of Health; Liverpool UK L69 3GB