1. St George's, University of London; Community Health Sciences; Cranmer Terrace Tooting London UK SW17 0RE
2. Peninsula Medical School; Primary Care Research Group; Smeall Building St Luke's Campus, Magdalen Rd Exeter Devon UK EX1 2LU
3. West China Hospital, Sichuan University; Chinese Cochrane Centre, Chinese EBM Centre; No. 37, Guo Xue Xiang Chengdu Sichuan China 610041