1. American mode
The “4+4” model established by
United States (US) is well known: medical students need to complete 4
years of general university education and receive a bachelor’s degree
before entering medical school. After admission to medical school,
medical students undergo four years of medical education, culminating in
an M.D. degree [23]. Earning an M.D. is a prerequisite for admission
to practice medicine. Medical students enter the residency training
after completing the medical school [24]. They register as general
practitioners after the first phase of training, and as specialists
after the second phase of training in related specialties. Many medical
schools in the US also promote the M.D. / Ph.D. program, which is to add
the Ph.D. training to M.D.[25]. It usually requires 4-5 years of
research training with the goal of developing leaders in the field of
medical research.