better collaboration among the diverse groups that can influence health. The Health Care and Community Services Project in Escondido, California, illustrates this kind of collaboration among diverse groups and the interconnectedness of health and social systems (see Box 2-2).

A resurgence of interest in broader definitions of health and its determinants is, in part, a response to the growing realization that investments in clinical care and personal preventive health services were not leading to commensurate gains in the health of populations (Evans and Stoddart, 1994). In the early 1970s, an ecologic or systems theory approach to understanding health and its determinants generated a multidimensional perspective. Some grouped the factors influencing health into four principal forces: (1) environment, (2) heredity, (3) lifestyles, and (4) health care services (Blum, 1981). A Canadian government white paper, often referred to as the Lalonde Report (Lalonde, 1974), brought wider attention to this "force-field" paradigm.

Initial responses tended to focus on individual behavior as the target of both responsibility and clinical and policy interventions. In the United States as well, the broadened emphasis on health promotion was aimed primarily at modifications of individual behavior that could be, and often were, undertaken as clinical and community interventions (USDHHS, 1991).

Responding, in part, to this focus on individuals largely to the exclusion of the communities in which they live. Evans and Stoddart (1994) proposed an expanded version of this model, illustrated in Figure 2-1, that identifies both the major influences on health and well-being and the dynamic relationships among them. In developing a model that is consistent with current knowledge about the determinants of health, they identified nine components of interest:

1. social environment,

2. physical environment,

3. genetic endowment,

4. individual response (behavior and biology),

5. health care,

6. disease,

7. health and function,

8. well-being, and

9. prosperity.