作者单位: | [1]Department ofSocial Medicine,University of Bristol,Bristol BS8 2PR [2]MRC BiostatisticsUnit, Institute of PublicHealth, CambridgeCB2 0SR [3]Clinical Epidemiologyand BiostatisticsUnit, MurdochChildren's ResearchInstitute, andUniversityof Melbourne,Parkville, Victoria3052, Australia [4]Cancer andStatistical MethodologyGroups, MRCClinical Trials Unit,London NW1 2DA [5]Medical StatisticsUnit, kondon Schoolof Hygiene andTropical Medicinelondon, WC1E 7HT [6]Depamnent ofPublic Health andPrimary Care, Instituteof Public Health,Cambridge [7]北京协和医科大学流行病学教研室, Instituteof Public Health,Cambridge |