From Framingham to North Karelia to U.S. Community-Based Prevention Programs: Negotiating Research Agenda for Coronary Heart Disease in the Second Half of the 20th Century

Abstract

In the United States in 1948, the newly formed National Heart Institute (NHI) responded to what its data showed as a rising tide of coronary heart disease (CHD) by underwriting new approaches to the elucidation of chronic disorders. In the process, it funded the application of epidemiology, previously almost exclusively concerned with communicable disease, to study CHD. With federal encouragement, CHD epidemiologists enriched research designs, helped develop the randomized controlled trial, and played a pioneering role in chronic disease prevention at the individual and population levels. While government funding was critical to the evolution of this rich scientific work, a vibrant epidemiological imagination was able to capitalize on decades of national political commitment to chronic disease research. Epidemiologists developed longitudinal studies meant to determine the relationship between well-measured clinical variables and subsequent CHD events. Here, consistent associations within and across populations, eventually reinforced by analyses of pooled data from multiple cohort investigations, demonstrated the existence of well-founded risk factors, but left open the question of causal inference based on observed relationships. After substantial ambivalence, the U.S. government, under pressure from epidemiologists, committed to an agenda of clinical trials to test that proposition. In addition, the results of the cohort studies elicited a demand by epidemiologists for a broader, population-wide approach, testing whether community-level models of risk factor modification through broad cultural change would demonstrate a reduction in the probability of disability and premature death from heart attack. To tell the story of the community studies and to analyze outcomes, we focus on the Minnesota Heart Health Program and the Finnish North Karelia Project. From the North Karelia experience, we find that health promotion campaigns in communities at very high risk of disease, where the population lives in traditional patterns and considerable poverty and is also unsophisticated in health knowledge and behaviors, are more likely to achieve major and measurable population effects. We argue that as chronic disease rates rise globally, and CHD rates increase in lower- and middle-income nations, as they have over the past several decades, population-level prevention interventions have become particularly relevant. But it remains to be seen whether the international community, prodded by its member states, can successfully reproduce the urgency and agenda-setting that sparked the successful epidemiologic and public health interventions in the affluent countries in the decades after World War II.