Data commentary

The data are subject to certain limitations which may affect their usefulness for some research problems. It is important to note, first of all, that the hospitals in the Ministry of Health system represent only about a third of hospitals in China. Hospitals under the military or civil affairs department, for example, are omitted. There are also some inconsistencies in reporting, most importantly, in reporting of date of founding. Most hospitals report actual date of founding, even when this occurred in the late Qing or Republican eras. Others report the date that the institution entered the Ministry of Health system, in 1950 or soon after. For this reason, counts of institution-years were started in 1950 rather than at actual dates of founding. It should be noted that the epidemiological stations, virtually all founding post-1949, are not subject to this defect. It should also be noted that institutions that closed prior to the date of listing (presumably few in number) are omitted.