Changes in smoking during a community-based cardiovascular disease intervention programme. The Coronary Risk Factor Study.

A prospective anti-smoking clinical trial was conducted as part of a coronary risk factor intervention study in three rural South African communities in the south-western Cape over a period of 4 years. The aim of this part of the study was to reduce smoking rates in two of the communities through application of high- and low-intensity intervention. The effect was evaluated by examining the net change in smoking habits, which was defined as the residual change in the intervention areas after allowing for change in the reference area. This paper presents the analyses of the estimated effect of the programme on the cohort aged 15-64 years at baseline who participated in the two surveys (4,087 subjects). The intervention programme among men in the high-intensity intervention area resulted in a reduction of 8.4% in smoking rates and 13.0% in the amount smoked per day. Among women in this area there was a reduction of 30.6% in smoking rates and 20.5% in amount smoked. Smoking and the amount smoked per day also decreased in the low-intensity intervention area, but less so than in the high-intensity intervention area. Smoking quit rates were strongly associated with initial smoking levels, with light smokers being significantly more successful quitters than heavy smokers. This study has proved that a community-based intervention programme can effectively reduce smoking.