Smoking as a determinant of the geographical pattern of cardiac events among women in an urban population

Abstract

Background: Smoking is the major risk factor for cardiac events in younger women and is most common in groups with the least favourable socioeconomic circumstances. Objective: To assess to what extent geographical differences in the female incidence of myocardial infarction in the city of Malmö in Sweden can be accounted for by smoking and to what extent intra-urban variances of smoking are related to socioeconomic circumstances. Method: Area specific prevalences of smokers is based on a sample of 17,319 women, aged 45—73 years. A comprehensive score was used to rank the 17 residential areas in terms of socioeconomic circumstances. Incidence of myocardial infarction and death is based on official statistics 1989— 97. Results: The area-specific prevalence of female smokers, which ranged from 17.5 to 32.5%, was inversely related to the socioeconomic score in 45- to 54 and 55- to 64-year-olds, r=-0.65 (p<0.05) and -0.59 (p<0.05). No correlation was found for women above 65 years of age. The annual age-adjusted incidence of cardiac events in the residential areas, which ranged from 151 to 414 per 100,000 person years, was strongly related to the prevalence of smokers, r=0.75 (p<0.001). Conclusion: Between 50% and 60% of the intra-urban variance of the female incidence of myocardial infarction was accounted for by smoking in this urban population. The geographical pattern of smoking was strongly related to inferior socioeconomic circumstances.