Novel epidemiologic study designs are often required to assess gene-environment interaction.
A design using only cases, without controls, is one of several approaches that have been proposed as more efficient alternatives to the typical random sampling of cases and controls.
However, it has not been pointed out that a case-only analysis estimates a different interaction parameter than does a traditional case-control analysis : The latter typically estimates departure from multiplicative population odds or rate ratios, depending on the method of control selection, while the former estimates departure from multiplicative risk ratios if genotype and environmental exposure are not associated in the population.
These parameters are approximately equal if the disease risk is small at all levels of the study variables.
The authors quantify the impact of allowing for higher disease risk among gene carriers, a relevant situation when the gene under study is highly penetrant.
Their findings show that the cross-product ratio computed from case-only data may be substantially smaller than the odds ratio computed from case-control data and may therefore underestimate either the population odds or the rate ratio.
Thus, to avoid misinterpretation of interaction parameters estimated from case-only data, the definition of multiplicative interaction should be made explicit.
Mots-clés Pascal : Santé et environnement, Gène, Interaction, Méthodologie, Biais méthodologique, Homme, Epidémiologie, Etude cas témoin
Mots-clés Pascal anglais : Health and environment, Gene, Interaction, Methodology, Methodological bias, Human, Epidemiology, Case control study
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0505103
Code Inist : 002B30A01A1. Création : 22/03/2000.