The study had a quasi-experimental design with two California cities, Salinas and Monterey, selected as intervention cities and three similar cities, San Luis Obispo, Modesto, and Santa Monica as control cities. The selection of cities was subject to several criteria including: location in Northern California; population exceeding 30,000 with a total of all five cities exceeding 300,000 to provide sufficient statistical power; ethnic, socioeconomic and demographic similarity; independence from other cities; no shared newspaper or electronic media between treatment and control cities and shared media markets between treatment cities; and independence of the two treatment cities. The education program began in 1980 after the completion of a baseline population survey and continued for eight years. Education methods included the use of television and radio, newspapers, books, pamphlets, and community programs developed through health departments, schools, voluntary organizations, hospitals and non-profit health service agencies.