This Article  • References  • Full text PDF  • Send to a friend  • Save in My Folder  • Save to citation manager  • Permissions  Citing Articles  • Contact me when this article is cited  Related Content  • Similar articles in JAMA  Social Bookmarking   What's this?

Philip R. J. Burch, PhD
Department of Medical Physics University of Leeds England

JAMA. 1983;249(11):1435.

	Since this article does not have an abstract, we have provided the first 150 words of the full text PDF and any section headings.

To the Editor.—

In favorable circumstances, a randomized, controlled intervention trial provides a test of the hypothesis that a "risk factor" is a causal factor. It is less widely recognized that analysis of the following kinds of evidence provides further tests: (1) sex- and age-specific death rates for coronary heart disease (CHD), (2) temporal trends in point 1, (3) mortality ratios by age and sex, (4) sex and age prevalence of persons with the risk factor, and (5) where available, temporal trends in point 4. Without going into tedious detail, it will be readily appreciated that if a risk factor is a causal factor, then changes in its level with age and time or both must manifest in the sex- and age-specific death rates for CHD. Exploiting the previously mentioned kinds of evidence, our problem is to discern whether the perturbations of death rates predicted by the causal hypothesis are . . . [Full Text PDF of this Article]

CiteULike    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter     What's this?