Department of General Practice, The School of General Practice and Continuing Education, Capital Medical University, Beijing 100069, China;
Department of General Practice, The School of General Practice and Continuing Education, Capital Medical University, Beijing 100069, China;
Department of General Medicine, Xuanwu Hospital of Capital Medical University, Beijing 100053, China;
Department of General Surgery, Xuanwu Hospital of Capital Medical University, Beijing 100053, China;