Try to analyze the differences in the hierarchy of health service organizations and urban-rural settings in China.

Answer: China's health service system is divided by urban and rural areas. In urban areas, the health organization system refers to the urban health service network; in rural areas, it refers to the three-tier rural health service network.

Urban health service system: Before the 1997 health care system reform: urban medical institutions are generally divided into three levels: city, district and street. Municipal medical and health institutions include city center hospitals, specialty hospitals and city center prevention and treatment institutions. District-level medical centers are the link between city-level institutions and street-level institutions. Street-level medical institutions are the most basic level of urban medical institutions, undertaking the most basic medical and preventive services for residents in the vicinity, etc. The reform of the medical and health care system in 1997 called for community health services as a new mode of service delivery based on the health or hygiene needs of regional residents from the perspective of the region and the population. At the same time, municipal health organizations have developed rapidly in terms of resource allocation and service level, while the function of district hospitals has gradually shrunk, and the most basic street-level health organizations have gradually been transformed into community health service centers. At present, many of China's urban health organizations have gradually developed from the original three levels into two levels of community health institutions and comprehensive health institutions.

Rural health service system: although China's current rural health conditions have been greatly improved, but due to the constraints of the rural natural conditions and health resources, the transportation to travel for medical treatment is inconvenient, and the affordability of medical treatment for farmers is low. Therefore, the specificity of rural areas determines that they cannot transition from a three-tier network to a two-tier one in a short period of time, as in the case of cities, and that the three-tier network will remain as the mainstay of the health organization system for a long time to come in the vast majority of rural areas. China's rural health service system consists of county and sub-county health organizations, forming a "three-tiered health-care network", in which county hospitals, health epidemiological stations, and maternity and child health-care centers are the centers, township health centres are the hubs, and village and group health centres are the basis of the three-tiered structure. This organizational system has played a very great role in the development of rural health in China since the founding of New China.