Applied Mathematics Colloquium
Abstract: The Talk will Focus on The Speaker's Role in the Production of "AMS 55" and of Plans for its Updating
Brown University Center for Statistical Sciences Seminar
Abstract: In designing new etiologic studies to uncover hitherto unknown risk factors it is pertinent to pose the question: is the incidence of the disease fully explained by the risk factors already identified? This research seeks to provide a conceptual framework for addressing this question. It will be demonstrated that the standardized incidence ratio of second primary melanoma can be used to estimate the total coefficient of variation in risk in the population, subject to some simplifying assumptions. The coefficient of variation estimated in this manner can thus be used as a benchmark against which to judge the contributions to this total variance of individual risk factors. A non-parametric estimator of the coefficient of variation attributable to a single risk factor on the basis of data from a case-control study will be presented and its properties examined using simulations. The categorization of a continuous risk factor can attenuate the estimate substantially, and estimation of the joint contribution of several risk factors will usually require statistical modelling. Results of the analysis indicate that the known risk factors for melanoma explain only a relatively small fraction of the population variation in risk, in contrast to conventional views on the topic.
<--- 1997 Index