economic-related risk factors to intervening biological systems and subsequent health outcomes;
identification of cultural strengths and health-enhancing resources resident in racial/ethnic groups and their role in accounting for resilience vis-à-vis socioeconomic inequality.
Previously listed priorities on predisease pathways, positive health, and environmentally induced gene expression place strong emphasis on preventing disease and promoting well-being at levels proximal to the individual. Collective properties of communities and social inequalities in turn address health at intermediate levels of aggregation. At the highest macro-level is population health. This report emphasizes four population issues: (1) time trends and spatial variation in population health; (2) accounting for such trends, with particular emphasis given to social and behavioral factors; (3) understanding linkages between the macroeconomy and population health; and (4) evaluating the health care system. An important crosscutting issue between these topics and the preceding priorities is the need for multilevel analyses that link population health dynamics to behavioral, psychosocial, and environmental factors (at both individual and intermediate levels of aggregation).
Recently documented population changes include declining rates of disability among the elderly and the growing utilization of alternative medicine. These require a broad range of in-depth studies to understand their origins, such as the role of behavioral and psychosocial factors in accounting for declining later-life disabilities. In the case of alternative therapies, what is needed is an integrated biopsychosocial characterization of their mechanisms of action and clear indications of what works, for whom, and why. With regard to children, deeper understanding of the causes of asthma, the most common chronic disease of childhood, lies in the future. Although several NIH initiatives are currently in progress to address gaps in current knowledge, investigations are needed to integrate data and findings from these studies into a unified multilevel explanation of how asthma comes about. These examples illustrate the central challenge for population-level research, namely, to identify the most important factors that drive changes in population health and to clarify their impact on society at large.
Evaluating the health care system is also a key priority. Of central importance are studies that will clarify how health outcomes are affected by managed care and explain the many conflicting findings regarding the effectiveness of medical care. Increased support for research on reciprocal relationships between population health and the macroeconomy is also a priority.