For some years, the principles of COPC have been embodied in publicly funded health programs such as neighborhood community health centers and the Indian Health Service. More recently, the private sector, especially HMOs, have recognized COPC as a way to achieve both economic and health goals. The community is the target population, that is, the group for which one practice has taken responsibility. At times, the community is clearly recognizable as is the case of a geographic community. In other instances, the community is less well defined, for example, the individuals enrolled in a health plan or a school population.
Communities share some common social, cultural, economic and political systems.
Finally, the COPC process is an important component in the model. It is described as four steps which do not necessarily need to occur sequentially. Several obstacles exist that have prevented COPC from moving more into the mainstream. Despite these problems, COPC can be integrated into practice in an incremental way. The staging criteria for COPC functions are presented in Table 1 .