The long-term effects of a cardiovascular disease prevention trial: the Stanford Five-City Project.

OBJECTIVES: This study examined long-term effects of a health-education intervention trial to reduce the risk of cardiovascular disease. METHODS: Surveys were conducted in California in two treatment and two control cities at baseline (1979/1980), after the 6-year intervention (1985/1986), and 3 years later at follow-up (1989/1990). Net treatment/control differences in risk-factor change were assessed for women and men 25 to 74 years of age. RESULTS: Blood pressure improvements observed in all cities from baseline to the end of the intervention were maintained during the follow-up in treatment but not control cities. Cholesterol levels continued to decline in all cities during follow-up. Smoking rates leveled out or increased slightly in treatment cities and continued to decline in control cities but did not yield significant net differences. Both coronary heart disease and all-cause mortality risk scores were maintained or continued to improve in treatment cities while leveling out or rebounding in control cities. CONCLUSIONS: These findings suggest that community-based cardiovascular disease prevention trials can have sustained effects. However, the modest net differences in risk factors suggest the need for new designs and interventions that will accelerate positive risk-factor change.