Premarketing clinical trials also tend to provide insufficient information on the drug’s efficacy and safety due to their artificial selection of patients. These trials frequently seek subjects who are as homogeneous as possible to reduce unexplained variability. For ethical reasons, subgroups such as the elderly, children, preg- nant women, or patients with other diseases are excluded. In addition to limited subjects, restricted study periods restrain the application of premarketing clinical trials into the real-world practice(3,4). The