Integrated primary care organizations: to what extent is integration occurring and why?

Integration in primary health care is occurring in many health-care systems without a clear understanding of the meaning of integration, its form and rationale. This literature review examines the definition and extent of integration, as well as the factors that might encourage it in the context of British integrated primary care organizations (IPCOs). Integration is complex and multifaceted. No commonly agreed definitions of integration have been developed and the range of dimensions examined in the empirical literature was limited. However, some of the dimensions examined in studies of IPCOs may be useful in better understanding the form integration takes. Few studies were designed to examine the determinants of integration or were explicitly based on theory. Research showed that the level of production and transaction costs was not related to the size of the IPCO, although in practice the attitudes of health professionals are likely to be more important influences on the extent of integration. To date, little progress has been made in explaining and measuring integration. If further integration in primary health care is warranted, more research is required to understand its nature, form and rationale.