In the Stanford study a three town design was chosen. In one test town only media based inputs were used, and in a second town the media were combined with community programmes. The effects in both test towns were compared with those in a control town. After two years the proportion of smokers had decreased by a net 5500/ in the media plus community pro- grammes town, suggesting a positive role for the media in health risk behaviour intervention. In 1980 the Stanford researchers extended their analysis to a major five town study of the role of the media in heart disease risk factor intervention.