00432nas a2200157 4500000000100000000000100001008004100002100001100043700001000054700001800064700001400082245014500096300001200241490000700253022001400260 2012 d1 aB. Cai1 aW. Xu1 aE. Bortnichak1 aD. Watson00aAn algorithm to identify medical practices common to both the General Practice Research Database and The Health Improvement Network database a770-7740 v21 a1053-8569