Period and cohort trends for mortality and cigarette consumption in England and Wales, 1946 to 1980, with emphasis on sex ratios

Abstract

In an earlier paper (Burch P. R. J. J Chron Dis 1981; 34: 87–103) changes in sex- and age-specific mortality from all causes of death in England and Wales were studied in relation to changes in sex- and age-specific cigarette consumption. The absence of a consistent correlation between the two variables, and the general characteristics of the data, suggested that studies of sex ratios might provide a better test of the hypothesis that the association between smoking and mortality has a causal basis. In this paper temporal changes in the sex ratio of cumulative cigarette consumption by cohort, and of smoking rates by age, are considered in relation to changes in the sex ratio of mortality. Again, no consistent correlations emerge and it is evident that factors other than smoking have played a dominant part in determining recent changes in the sex ratio of mortality in all age groups from 35–39 to 80–84 years. Among these “other factors” are birth cohort effects that can be attributed, in part, to birth cohort changes in the sex ratio of mortality from bronchitis and emphysema. The present results, together with other evidence ( vide supra; and Burch P. R. J. J Chron Dis 1984; 37: 148–156), show that great care needs to be exercised when attempts are made to deduce causation from epidemiologic surveys.