1. London School of Hygiene & Tropical Medicine; Cochrane Injuries Group; Keppel Street London UK WC1E 7HT
2. Wakayama Medical University; School of Health and Nursing Science; 580 Mikazura Wakayama Japan 641-0011
3. University of Hertfordshire; Centre for Research in Primary and Community Care; College Lane Hatfield Hertfordshire UK AL10 9PN
4. Chelsea and Westminister Hospital; Imperial College School of Medicine; London UK SW10 9NH