Establishing research priorities in etiologic epidemiology

PURPOSE: A major goal of epidemiology is to discover the causes of disease in populations. The aim of this study was to develop a method for establish ing research priorities within this very broad area of scientific inquiry. METHODS: While the approach is applicable to many diseases, cancer was used here, in part because of its importance to both individuals and government s. Measures of disease were estimated from data in the Ontario Cancer Regis try, and combined to yield a single assessment of impact for each cancer si te. Measures of exposure prevalence were identified from recent population health surveys. Cross-classification by disease and exposure rankings yield ed a matrix of scores of "relative importance" for each cancer-exposure com bination. Onto this matrix was overlaid: 1) estimates of statistical power for examining each association; 2) biological plausibility of each associat ion; and 3) strength of the epidemiological evidence supporting each associ ation. RESULTS: The disease exposure matrix, viewed in light of statistical power, biological plausibility, and current epidemiological evidence, yielded, in the examples shown, some potentially interesting yet understudied associat ions (e.g., non-Hodgkin lymphoma (NHL) and certain aspects of dietary intak e). CONCLUSIONS: The associations identified within the research hierarchy sugg est not only new avenues for etiologic research, but also priorities for re search focus. (C) 1998 Elsevier Science Inc.